Fix: correct regex for file-preview URL re-signing (#25620)
Fixes #25619
The regex patterns for file-preview and image-preview contained an unescaped `?`,
which caused incorrect matches such as `file-previe` or `image-previw`.
This led to malformed URLs being incorrectly re-signed.
Changes:
- Escape `?` in both file-preview and image-preview regex patterns.
- Ensure only valid URLs are re-signed.
Added unit tests to cover:
- Valid file-preview and image-preview URLs (correctly re-signed).
- Misspelled file/image preview URLs (no longer incorrectly matched).
Other:
- Fix a deprecated function `datetime.utcnow()`
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Asuka Minato <i@asukaminato.eu.org>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>