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

从 build.bat 开始，跟踪解释器构建期间测试项目文件的构建方式。添加一个可选择启用的路径，在保留默认行为的同时跳过这些文件，然后验证手动解释器构建或嵌入式构建可以在没有测试项目的情况下完成。