Add test for dotnet test with UseAppHost=false in MTP

[Copilot]

This PR adds a test case to verify that Microsoft Testing Platform (MTP) projects work correctly when UseAppHost=false is configured.

Background

When UseAppHost=false, .NET projects don't generate an executable host and instead rely on dotnet exec mydll.dll for execution. This scenario needed test coverage to ensure MTP projects function properly in this configuration.

Changes

• Added test case RunMTPProjectWithUseAppHostFalse_ShouldWork that verifies MTP projects execute successfully with UseAppHost=false
• Created test asset TestProjectMTPWithUseAppHostFalse combining MTP configuration with UseAppHost=false
• Added dotnet.config file specifying Microsoft.Testing.Platform usage
• Made package references conditional to avoid network dependencies during testing

The test ensures that the basic functionality of running MTP projects with UseAppHost=false works as expected, providing confidence that this configuration is properly supported.

Fixes #49718.

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[Youssef1313]

@copilot Please create dotnet.config in test/TestAssets/TestProjects/TestProjectMTPWithUseAppHostFalse` specifying Microsoft.Testing.Platform.

[Youssef1313]

@copilot Please revert the changes in TestApplication.cs

[Copilot]

@copilot Please create dotnet.config in test/TestAssets/TestProjects/TestProjectMTPWithUseAppHostFalse` specifying Microsoft.Testing.Platform.

Created dotnet.config in test/TestAssets/TestProjects/TestProjectMTPWithUseAppHostFalse specifying Microsoft.Testing.Platform. Added in commit 628f1b7.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• 5rqvsblobprodcus385.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/sdk/sdk/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:false /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=true /home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25377.103/tools/Build.proj /bl:"/home/REDACTED/work/sdk/sdk/artifacts/log/Release/Build.binlog" /p:Configuration=Release /p:RepoRoot=/home/REDACTED/work/sdk/sdk/ /p:Restore=true /p:Build=true /p:DotNetBuild=false /p:DotNetBuildSourceOnly=false /p:DotNetBuildFromVMR=false /p:Rebuild=false /p:Test=false /p:Pack=false /p:IntegrationTest=false /p:PerformanceTest=false /p:Sign=false /p:Publish=false /p:RestoreStaticGraphEnableBinaryLogger=true /p:SkipUsingCrossgen=true /p:SkipBuildingInstallers=true -logger:/home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25377.103/tools/net/Microsoft.DotNet.ArcadeLogging.dll (dns block)
• pe4vsblobprodcus351.vsblob.vsassets.io
  • Triggering command: /home/REDACTED/work/sdk/sdk/.dotnet/dotnet msbuild /m /nologo /clp:Summary /v:minimal /nr:false /warnaserror /p:TreatWarningsAsErrors=true /p:ContinuousIntegrationBuild=true /home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25377.103/tools/Build.proj /bl:"/home/REDACTED/work/sdk/sdk/artifacts/log/Release/Build.binlog" /p:Configuration=Release /p:RepoRoot=/home/REDACTED/work/sdk/sdk/ /p:Restore=true /p:Build=true /p:DotNetBuild=false /p:DotNetBuildSourceOnly=false /p:DotNetBuildFromVMR=false /p:Rebuild=false /p:Test=false /p:Pack=false /p:IntegrationTest=false /p:PerformanceTest=false /p:Sign=false /p:Publish=false /p:RestoreStaticGraphEnableBinaryLogger=true /p:SkipUsingCrossgen=true /p:SkipBuildingInstallers=true -logger:/home/REDACTED/.nuget/packages/microsoft.dotnet.arcade.sdk/10.0.0-beta.25377.103/tools/net/Microsoft.DotNet.ArcadeLogging.dll (dns block)

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[Copilot]

Pull Request Overview

This PR adds test coverage to verify that Microsoft Testing Platform (MTP) projects work correctly when UseAppHost=false is configured. This ensures that MTP projects can run using dotnet exec mydll.dll instead of generating an executable host.

• Added a new test case RunMTPProjectWithUseAppHostFalse_ShouldWork to verify MTP functionality with UseAppHost=false
• Created a test asset project with minimal MTP configuration and UseAppHost=false setting
• Implemented conditional package references to avoid network dependencies during testing

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
GivenDotnetTestBuildsAndRunsTests.cs	Added test method to verify MTP projects work with UseAppHost=false
dotnet.config	Configuration file enabling Microsoft Testing Platform for the test asset
TestProjectMTPWithUseAppHostFalse.csproj	Project file with UseAppHost=false and conditional MTP package reference
Program.cs	Minimal MTP test implementation with dummy test adapter