Fix double-publish compression error in TestContentPackage

[ilonatommy]

Trying to fix the reported race issue: #61178 (comment). The methodology used is same as in #65675, we just extend it to TestContentPackage asset.

[dotnet-policy-service]

Hey @dotnet/aspnet-build, looks like this PR is something you want to take a look at.

[Copilot]

Pull request overview

Extends the existing “skip referenced-project publish assets” pattern used in Components E2E trimmed publishing to TestContentPackage, preventing redundant Static Web Assets publish work that can race when multiple projects publish concurrently.

Changes:

• Adds an MSBuild conditional override for StaticWebAssetsGetPublishAssetsTargets when _SkipReferencedProjectPublishAssets=true.
• Introduces a no-op target _SkipGetPublishAssetsForTrimmedBuild to short-circuit Static Web Assets’ referenced-project publish-assets execution.

[wtgodbe]

One clarifying question

[wtgodbe]

Are we sure _SkipReferencedProjectPublishAssets will be set here when we need it to?

[wtgodbe]

It looks like the issue is that  Components.TestServer.csproj references BasicTestApp.csproj and Components.WasmMinimal.csproj, both of which reference this project w/ identical global properties, so there's a race

[ilonatommy]

Yes, the race is the reason for double publish. As you say, we have something like

Components.TestServer
|___BasicTestApp
|     |___TestContentPackage
|___ Components.WasmMinimal
      |___TestContentPackage

and when E2ETests.csproj is built we have both: BasicTestApp.csproj

aspnetcore/src/Components/test/E2ETest/Microsoft.AspNetCore.Components.E2ETests.csproj

Line 101 in 2e05e26

<ProjectReference Include="..\testassets\BasicTestApp\BasicTestApp.csproj" Targets="Build;Publish" Properties="BuildProjectReferences=false;TestTrimmedApps=true;PublishDir=$(MSBuildThisFileDirectory)$(OutputPath)trimmed\BasicTestApp\" />

and Components.TestServer

aspnetcore/src/Components/test/E2ETest/Microsoft.AspNetCore.Components.E2ETests.csproj

Line 109 in 2e05e26

<ProjectReference Include="..\testassets\Components.TestServer\Components.TestServer.csproj" Targets="Build;Publish" Properties="BuildProjectReferences=false;TestTrimmedApps=true;_SkipReferencedProjectPublishAssets=true;PublishDir=$(MSBuildThisFileDirectory)$(OutputPath)trimmed\Components.TestServer\;" />

publish triggered. The first one is missing _SkipReferencedProjectPublishAssets property, the latter has it set. That's good. That means that one of the publishes will be skipped, the other one won't. That eliminate the race. Do I get it right?