Poor experience for .NET tool installed by unsupported SDK

Installing a .NET global tool with an SDK that is lower than the tool's required SDK leads to a confusing error message:

```plain
The settings file in the tool's NuGet package is invalid: Settings file 'DotnetToolSettings.xml' was not found in the package.
Tool 'azuresigntool' failed to install. Contact the tool author for assistance.
```

`AzureSignTool` 7.0.0 requires .NET 10, but if a user has .NET 8 installed, they will receive that message.

Steps to reproduce:

1. Install .NET SDK 8.0.xxx. Ensure anything newer than 8.0 is _not_ installed.
2. Do `dotnet tool install --global AzureSignTool --version 7.0.0`
3. Observe the error message.

Ideally, something like "AzureSignTool 7.0.0 requires .NET 10. Please install .NET 10 \" is displayed.