Including a tool causes assembly conflicts.

### What You Are Seeing?
When I include the tool for Cake.Squirrel

```
#tool Squirrel.Windows
```

along with my own custom addin that depends on System.IO.Compression I end up getting a MissingMethodException for the System.IO.Compression.ZipFile.OpenRead method. I believe there is a known historical problem with that function missing from the net46 dll. Somehow including that tool (which is a C# nuget package with assembly references for integrating squirrel with a .net app along with the exe's) messes with the assembly resolution when running the script.

if I remove that tool directive I can execute the ZipFile.OpenRead function but then the cake.squirrel calls error because the tool is missing. I suppose I can move the tool installation to the bootstrapper but I also thought I heard the plan was to not need the bootstrapper in the future?

### What is Expected?

I expect tools to just download and install the exes in the tools directory and not reference the assemblies. If I wanted those I would list it as an addin.

### What version of Cake are you using?
Version 0.30.0+Branch.main.Sha.cab58db40b02346e562531be27fcaa5ea51a3312

### Are you running on a 32 or 64 bit system?
64bit

### What environment are you running on? Windows? Linux? Mac?
Windows

### Are you running on a CI Server? If so, which one?
Nope

### How Did You Get This To Happen? (Steps to Reproduce)
The first paragraph describes my problem.

### Output Log
```
powershell -ExecutionPolicy ByPass -File build.ps1 -script "d:\\project_template.cake" -target "Build-Squirrel-Package" -verbosity diagnostic
Preparing to run build script...
Running build script...
Module directory does not exist.
NuGet.config not found.
Analyzing build script...
Analyzing D://project_template.cake...
Processing build script...
Installing tools...
Found package 'Squirrel.Windows 1.9.0' in 'd://tools'.
Package squirrel.windows.1.9.0 has already been installed.
Successfully installed 'Squirrel.Windows 1.9.0' to d://tools
Executing nuget actions took 27.59 ms
Verifying assembly 'Cake.CustomAddin, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
Adding assembly reference to mscorlib.dll...
Adding assembly reference to System.Core.dll...
Adding assembly reference to Cake.Core.dll...
Adding assembly reference to Cake.Common.dll...
Adding assembly reference to Cake.exe...
Adding assembly reference to System.dll...
Adding assembly reference to System.Xml.dll...
Adding assembly reference to System.Xml.Linq.dll...
Adding assembly reference to System.Data.dll...
Adding assembly reference to System.Runtime.dll...
Adding assembly reference to System.Collections.dll...
Adding assembly reference to netstandard.dll...
Adding assembly reference to Cake.CustomAddin.dll...
Importing namespace Cake.Common...
Importing namespace Cake.Common.Build...
Importing namespace Cake.Common.Build.AppVeyor...
Importing namespace Cake.Common.Build.AppVeyor.Data...
Importing namespace Cake.Common.Build.Bamboo...
Importing namespace Cake.Common.Build.Bamboo.Data...
Importing namespace Cake.Common.Build.BitbucketPipelines...
Importing namespace Cake.Common.Build.BitbucketPipelines.Data...
Importing namespace Cake.Common.Build.Bitrise...
Importing namespace Cake.Common.Build.Bitrise.Data...
Importing namespace Cake.Common.Build.ContinuaCI...
Importing namespace Cake.Common.Build.ContinuaCI.Data...
Importing namespace Cake.Common.Build.GitLabCI...
Importing namespace Cake.Common.Build.GitLabCI.Data...
Importing namespace Cake.Common.Build.GoCD...
Importing namespace Cake.Common.Build.GoCD.Data...
Importing namespace Cake.Common.Build.Jenkins...
Importing namespace Cake.Common.Build.Jenkins.Data...
Importing namespace Cake.Common.Build.MyGet...
Importing namespace Cake.Common.Build.TeamCity...
Importing namespace Cake.Common.Build.TFBuild...
Importing namespace Cake.Common.Build.TFBuild.Data...
Importing namespace Cake.Common.Build.TravisCI...
Importing namespace Cake.Common.Build.TravisCI.Data...
Importing namespace Cake.Common.Diagnostics...
Importing namespace Cake.Common.IO...
Importing namespace Cake.Common.IO.Paths...
Importing namespace Cake.Common.Net...
Importing namespace Cake.Common.Security...
Importing namespace Cake.Common.Solution...
Importing namespace Cake.Common.Solution.Project...
Importing namespace Cake.Common.Solution.Project.Properties...
Importing namespace Cake.Common.Solution.Project.XmlDoc...
Importing namespace Cake.Common.Text...
Importing namespace Cake.Common.Tools...
Importing namespace Cake.Common.Tools.Cake...
Importing namespace Cake.Common.Tools.Chocolatey...
Importing namespace Cake.Common.Tools.Chocolatey.ApiKey...
Importing namespace Cake.Common.Tools.Chocolatey.Config...
Importing namespace Cake.Common.Tools.Chocolatey.Download...
Importing namespace Cake.Common.Tools.Chocolatey.Features...
Importing namespace Cake.Common.Tools.Chocolatey.Install...
Importing namespace Cake.Common.Tools.Chocolatey.New...
Importing namespace Cake.Common.Tools.Chocolatey.Pack...
Importing namespace Cake.Common.Tools.Chocolatey.Pin...
Importing namespace Cake.Common.Tools.Chocolatey.Push...
Importing namespace Cake.Common.Tools.Chocolatey.Sources...
Importing namespace Cake.Common.Tools.Chocolatey.Uninstall...
Importing namespace Cake.Common.Tools.Chocolatey.Upgrade...
Importing namespace Cake.Common.Tools.DotCover...
Importing namespace Cake.Common.Tools.DotCover.Analyse...
Importing namespace Cake.Common.Tools.DotCover.Cover...
Importing namespace Cake.Common.Tools.DotCover.Merge...
Importing namespace Cake.Common.Tools.DotCover.Report...
Importing namespace Cake.Common.Tools.DotNetCore...
Importing namespace Cake.Common.Tools.DotNetCore.Build...
Importing namespace Cake.Common.Tools.DotNetCore.Clean...
Importing namespace Cake.Common.Tools.DotNetCore.Execute...
Importing namespace Cake.Common.Tools.DotNetCore.MSBuild...
Importing namespace Cake.Common.Tools.DotNetCore.NuGet.Delete...
Importing namespace Cake.Common.Tools.DotNetCore.NuGet.Push...
Importing namespace Cake.Common.Tools.DotNetCore.Pack...
Importing namespace Cake.Common.Tools.DotNetCore.Publish...
Importing namespace Cake.Common.Tools.DotNetCore.Restore...
Importing namespace Cake.Common.Tools.DotNetCore.Run...
Importing namespace Cake.Common.Tools.DotNetCore.Test...
Importing namespace Cake.Common.Tools.DotNetCore.Tool...
Importing namespace Cake.Common.Tools.DotNetCore.VSTest...
Importing namespace Cake.Common.Tools.DupFinder...
Importing namespace Cake.Common.Tools.Fixie...
Importing namespace Cake.Common.Tools.GitLink...
Importing namespace Cake.Common.Tools.GitReleaseManager...
Importing namespace Cake.Common.Tools.GitReleaseManager.AddAssets...
Importing namespace Cake.Common.Tools.GitReleaseManager.Close...
Importing namespace Cake.Common.Tools.GitReleaseManager.Create...
Importing namespace Cake.Common.Tools.GitReleaseManager.Export...
Importing namespace Cake.Common.Tools.GitReleaseManager.Publish...
Importing namespace Cake.Common.Tools.GitReleaseNotes...
Importing namespace Cake.Common.Tools.GitVersion...
Importing namespace Cake.Common.Tools.ILMerge...
Importing namespace Cake.Common.Tools.ILRepack...
Importing namespace Cake.Common.Tools.InnoSetup...
Importing namespace Cake.Common.Tools.InspectCode...
Importing namespace Cake.Common.Tools.MSBuild...
Importing namespace Cake.Common.Tools.MSpec...
Importing namespace Cake.Common.Tools.MSTest...
Importing namespace Cake.Common.Tools.NSIS...
Importing namespace Cake.Common.Tools.NuGet...
Importing namespace Cake.Common.Tools.NuGet.Add...
Importing namespace Cake.Common.Tools.NuGet.Init...
Importing namespace Cake.Common.Tools.NuGet.Install...
Importing namespace Cake.Common.Tools.NuGet.List...
Importing namespace Cake.Common.Tools.NuGet.Pack...
Importing namespace Cake.Common.Tools.NuGet.Push...
Importing namespace Cake.Common.Tools.NuGet.Restore...
Importing namespace Cake.Common.Tools.NuGet.SetApiKey...
Importing namespace Cake.Common.Tools.NuGet.SetProxy...
Importing namespace Cake.Common.Tools.NuGet.Sources...
Importing namespace Cake.Common.Tools.NuGet.Update...
Importing namespace Cake.Common.Tools.NUnit...
Importing namespace Cake.Common.Tools.OctopusDeploy...
Importing namespace Cake.Common.Tools.OpenCover...
Importing namespace Cake.Common.Tools.ReportGenerator...
Importing namespace Cake.Common.Tools.ReportUnit...
Importing namespace Cake.Common.Tools.Roundhouse...
Importing namespace Cake.Common.Tools.SignTool...
Importing namespace Cake.Common.Tools.SpecFlow...
Importing namespace Cake.Common.Tools.SpecFlow.StepDefinitionReport...
Importing namespace Cake.Common.Tools.SpecFlow.TestExecutionReport...
Importing namespace Cake.Common.Tools.TextTransform...
Importing namespace Cake.Common.Tools.VSTest...
Importing namespace Cake.Common.Tools.VSWhere...
Importing namespace Cake.Common.Tools.VSWhere.All...
Importing namespace Cake.Common.Tools.VSWhere.Latest...
Importing namespace Cake.Common.Tools.VSWhere.Legacy...
Importing namespace Cake.Common.Tools.VSWhere.Product...
Importing namespace Cake.Common.Tools.WiX...
Importing namespace Cake.Common.Tools.WiX.Heat...
Importing namespace Cake.Common.Tools.XBuild...
Importing namespace Cake.Common.Tools.XUnit...
Importing namespace Cake.Common.Xml...
Importing namespace Cake.Core...
Importing namespace Cake.Core.Diagnostics...
Importing namespace Cake.Core.IO...
Importing namespace Cake.Core.Scripting...
Importing namespace Cake.CustomAddin...
Importing namespace System...
Importing namespace System.Collections.Generic...
Importing namespace System.IO...
Importing namespace System.Linq...
Importing namespace System.Text...
Importing namespace System.Threading.Tasks...
Compiling build script...

----------------------------------------
Setup
----------------------------------------
Executing custom setup action...
Running tasks...

========================================
Build-Squirrel-Package
========================================
Executing task: Build-Squirrel-Package

An error occurred when executing task 'Build-Squirrel-Package'.

----------------------------------------
Teardown
----------------------------------------
Executing custom teardown action...
Finished running tasks.
Error: System.AggregateException: One or more errors occurred. ---> System.MissingMethodException: Method not found: 'System.IO.Compression.ZipArchive System.IO.Compression.ZipFile.OpenRead(System.String)'.

at Cake.CustomAddin.Aliases.ValidateSquirrelNugetPackages(ICakeContext context, PackageBuildInfo buildInfo, DirectoryPath outputDirectory) in
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at Submission#0.<<>b__0_5>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeTask.d__43.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.DefaultExecutionStrategy.d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__31.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Scripting.BuildScriptHost.d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.Scripting.ScriptHost.RunTarget(String target)
at Submission#0.<>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.CodeAnalysis.Scripting.ScriptExecutionState.d__9`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.CodeAnalysis.Scripting.Script`1.d__21.MoveNext()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at Cake.Scripting.Roslyn.RoslynScriptSession.Execute(Script script)
at Cake.Core.Scripting.ScriptRunner.Run(IScriptHost host, FilePath scriptPath, IDictionary`2 arguments)
at Cake.Commands.BuildCommand.Execute(CakeOptions options)
at Cake.CakeApplication.Run(CakeOptions options)
at Cake.Program.Main()
---> (Inner Exception #0) System.MissingMethodException: Method not found: 'System.IO.Compression.ZipArchive System.IO.Compression.ZipFile.OpenRead(System.String)'.

at Cake.CustomAddin.Aliases.ValidateSquirrelNugetPackages(ICakeContext context, PackageBuildInfo buildInfo, DirectoryPath outputDirectory) in
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at Submission#0.<<>b__0_5>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeTask.d__43.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.DefaultExecutionStrategy.d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__31.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__28.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.CakeEngine.d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Scripting.BuildScriptHost.d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Cake.Core.Scripting.ScriptHost.RunTarget(String target)
at Submission#0.<>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.CodeAnalysis.Scripting.ScriptExecutionState.d__9`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.CodeAnalysis.Scripting.Script`1.d__21.MoveNext()<---
```

Start with the build.ps1 execution and the #tool Squirrel.Windows directive, then reproduce the conflict alongside the custom addin's System.IO.Compression.ZipFile.OpenRead call using diagnostic verbosity. Done means the tool's executables remain available for Cake.Squirrel calls without introducing assembly references that cause the custom addin's method to fail.

Written by the indexing model from the issue text.