Fix tool projects so they don't remove apphosts when publishing (not packing)

[baronfel]

Fixes #49799

The PackTool targets were unconditionally overwriting the UseAppHost and related properties at evaluation-time. This results in publishes of the projects not having AppHosts when they were expected to.

Instead of modifying the way that the projects are Published, we now use knowledge of the intent of the Publish to determine if the apphost/binary should be included in the generated tool package.

[Copilot]

Pull Request Overview

This PR fixes a bug where tool projects were incorrectly removing apphosts during publish operations. The issue was that PackTool targets were unconditionally overwriting UseAppHost and related properties at evaluation time, causing published tool projects to lack AppHosts when they were expected.

• Moved UseAppHost property modifications from evaluation-time to a target that runs early in the pack process
• Added a test to verify that tool projects can publish with apphosts correctly
• Relocated ToolCommandRunner property group to be set within the SetPackToolProperties target

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
test/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishAToolProject.cs	Added new test class to verify tool projects can publish with apphosts
src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.PackTool.targets	Moved UseAppHost and ToolCommandRunner property settings from evaluation-time to SetPackToolProperties target

Comments suppressed due to low confidence (2)

test/Microsoft.NET.Publish.Tests/GivenThatWeWantToPublishAToolProject.cs:35

• The test should verify that the publish command executed successfully before checking for the apphost file. Consider adding .Should().Pass() or similar assertion after Execute().

            publishCommand.Execute();

[baronfel]

/backport to release/10.0.1xx-preview7

[github-actions]

Started backporting to release/10.0.1xx-preview7: https://github.com/dotnet/sdk/actions/runs/16449036667