Replace all contexts in tests with go1.24 t.Context()
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Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Fix#31361, and add tests
And this PR introduces an undocumented & debug-purpose-only config
option: `USE_SUB_URL_PATH`. It does nothing for end users, it only helps
the development of sub-path related problems.
And also fix#31366
Co-authored-by: @ExplodingDragon