Bump bleach from 6.3.0 to 6.4.0

Bumps [bleach](https://github.com/mozilla/bleach) from 6.3.0 to 6.4.0.
- [Changelog](https://github.com/mozilla/bleach/blob/main/CHANGES)
- [Commits](mozilla/bleach@v6.3.0...v6.4.0)

---
updated-dependencies:
- dependency-name: bleach
  dependency-version: 6.4.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -7,7 +7,7 @@ async-lru==2.3.0
 attrs==26.1.0
 babel==2.18.0
 beautifulsoup4==4.14.3
-bleach==6.3.0
+bleach==6.4.0
 certifi==2026.2.25
 cffi==2.0.0
 charset-normalizer==3.4.7