Cannot debug Nunit Parametrized TestFixture

## Problem description
I downloaded example Parametrized TestFixture file from: [Nunit Parametrized TestFixture](https://docs.nunit.org/articles/nunit/writing-tests/attributes/testfixture.html#parameterized-test-fixtures) and when i want to debug in VSCode it fails with exception System.ArgumentException: Selected argument cannot be null or empty. (Parameter 'tests'). When I run "dotnet test" from terminal test start without any issue.

## Environment data
`dotnet --info` output:
Host:
Version: 6.0.16
Architecture: x64
Commit: 1e620a42e7

.NET SDKs installed:
3.1.426 [C:\Program Files\dotnet\sdk]
6.0.408 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
VS Code version:
Version: 1.78.2 (user setup)
Commit: b3e4e68a0bc097f0ae7907b217c1119af9e03435
Date: 2023-05-10T14:39:26.248Z
Electron: 22.5.2
Chromium: 108.0.5359.215
Node.js: 16.17.1
V8: 10.8.168.25-electron.0
OS: Windows_NT x64 10.0.22621
Sandboxed: Yes
C# Extension version:

## OmniSharp log
[info]: OmniSharp.Stdio.Host
Starting OmniSharp on Windows 10.0.22621.0 (x64)
[info]: OmniSharp.Services.DotNetCliService
Checking the 'DOTNET_ROOT' environment variable to find a .NET SDK
[info]: OmniSharp.Services.DotNetCliService
Using the 'dotnet' on the PATH.
[info]: OmniSharp.Services.DotNetCliService
DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 1 MSBuild instance(s)
1: .NET Core SDK 6.0.408 17.3.2 - "C:\Program Files\dotnet\sdk\6.0.408\"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: .NET Core SDK 6.0.408 17.3.2 - "C:\Program Files\dotnet\sdk\6.0.408\"
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.Cake.CakeProjectSystem
Detecting Cake files in 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit'.
[info]: OmniSharp.Cake.CakeProjectSystem
Did not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
No solution files found in 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit'
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit\parametrizedNunit.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
Detecting CSX files in 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit'.
[info]: OmniSharp.Script.ScriptProjectSystem
Did not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
Configuration finished.
[info]: OmniSharp.Stdio.Host
Omnisharp server running using Stdio at location 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit' on host 9700.
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit\parametrizedNunit.csproj
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit\parametrizedNunit.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Adding project 'c:\Users\kolarik\Downloads\nunitTest\parametrizedNunit\parametrizedNunit.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Update project: parametrizedNunit
Received response for /v2/getcodeactions but could not find request.
Received response for /v2/gotodefinition but could not find request.
[info]: OmniSharp.DotNetTest.VSTestManager
read: {"MessageType":"TestSession.Connected","Payload":null}
[info]: OmniSharp.DotNetTest.VSTestManager
read: {"MessageType":"ProtocolVersion","Payload":1}
[info]: OmniSharp.DotNetTest.DebugSessionManager
Debug session started.
[warn]: OmniSharp.Stdio.Host
************ Request ************
{
"Type": "request",
"Seq": 81,
"Command": "/v2/debugtest/getstartinfo",
"Arguments": {
"FileName": "c:\\Users\\kolarik\\Downloads\\nunitTest\\parametrizedNunit\\UnitTest1.cs",
"MethodName": "parametrizedNunit.ParameterizedTestFixture.TestInequality",
"TestFrameworkName": "nunit",
"TargetFrameworkVersion": ".NETCoreApp,Version=v6.0",
"NoBuild": false
}
}
[fail]: OmniSharp.Stdio.Host
************ Response (4187.5981ms) ************
{
"Request_seq": 81,
"Command": "/v2/debugtest/getstartinfo",
"Running": true,
"Success": false,
"Message": "\"System.NullReferenceException: Object reference not set to an instance of an object.\\r\\n at OmniSharp.DotNetTest.VSTestManager.DebugGetStartInfoAsync(String[] methodNames, String runSettings, String testFrameworkName, String targetFrameworkVersion, CancellationToken cancellationToken) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.DotNetTest\\\\VSTestManager.cs:line 170\\r\\n at OmniSharp.Endpoint.EndpointHandler`2.GetFirstNotEmptyResponseFromHandlers(ExportHandler`2[] handlers, TRequest request) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.Host\\\\Endpoint\\\\EndpointHandler.cs:line 217\\r\\n at OmniSharp.Endpoint.EndpointHandler`2.HandleRequestForLanguage(String language, TRequest request, RequestPacket packet) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.Host\\\\Endpoint\\\\EndpointHandler.cs:line 233\\r\\n at OmniSharp.Endpoint.EndpointHandler`2.Process(RequestPacket packet, LanguageModel model, JToken requestObject) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.Host\\\\Endpoint\\\\EndpointHandler.cs:line 142\\r\\n at OmniSharp.Stdio.Host.HandleRequest(String json, ILogger logger) in D:\\\\a\\\\1\\\\s\\\\src\\\\OmniSharp.Stdio\\\\Host.cs:line 258\"",
"Body": null,
"Seq": 284,
"Type": "response"
## .NET Test log
NUnit Adapter 4.2.0.0: Test discovery starting
NUnit Adapter 4.2.0.0: Test discovery complete
System.ArgumentException: Selected argument cannot be null or empty.. (Parameter 'tests')
at Microsoft.VisualStudio.TestPlatform.ObjectModel.ValidateArg.NotNullOrEmpty[T](IEnumerable`1 arg, String parameterName)
at Microsoft.VisualStudio.TestPlatform.ObjectModel.Client.TestRunCriteria..ctor(IEnumerable`1 tests, Int64 frequencyOfRunStatsChangeEvent, Boolean keepAlive, String testSettings, TimeSpan runStatsChangeEventTimeout, ITestHostLauncher testHostLauncher, TestSessionInfo testSessionInfo, Boolean debugEnabledForTestSession)
at Microsoft.VisualStudio.TestPlatform.CommandLine.TestPlatformHelpers.TestRequestManager.RunTests(TestRunRequestPayload testRunRequestPayload, ITestHostLauncher3 testHostLauncher, ITestRunEventsRegistrar testRunEventsRegistrar, ProtocolConfig protocolConfig)
at Microsoft.VisualStudio.TestPlatform.Client.DesignMode.DesignModeClient.<>c__DisplayClass23_0.b__0()
## Steps to reproduce

1. Download this exmaple project [parametrizedNunit.zip](https://github.com/OmniSharp/omnisharp-vscode/files/11590570/parametrizedNunit.zip)
2. Open in VSCode
3. Run dotnet restore / dotnet build
4. Try to debug some test

## Expected behavior
Debug mode is stared

## Actual behavior
System.ArgumentException: Selected argument cannot be null or empty.. (Parameter 'tests') is shown.