Allow one to use build.bat to skip building test project files entirely.

Only useful if you wish to manually compile the interpreter in order to build a manual embed zip file to reflect changes in a branch from a clone of the repository. This would need to be opt-in and not by default though. Also allows those who only want to clone python just to build to skip them without needing to manually clean up the built test projects by hand and accidentally delete something important instead.

Great for:

• wanting a change before a new point release is made.
• for checking any local changes outside of tests with a project that uses an embedded interpreter.
• those who clones the repository only to build python itself and not wanting to tests to be built at all.

Applies to:

• 3.12
• 3.13
• 3.14
• main

build.bat から始めて、インタープリターのビルド中にテストプロジェクトのファイルがどのようにビルドされるかを追跡します。デフォルトの動作を維持したまま、それらのファイルをスキップする opt-in の経路を追加し、その後、テストプロジェクトなしで手動インタープリターまたは組み込みビルドが完了することを確認します。