Bumps bleach from 6.3.0 to 6.4.0.

Sourced from bleach's changelog.

Version 6.4.0 (June 5th, 2026)

NOTE: 2026-06-05: Bleach is no longer maintained. There will be no future releases including for security issues. See issue: <https://github.com/mozilla/bleach/issues/698>__

Backwards incompatible changes

• Dropped support for pypy 3.10. (#764)

Security fixes

• Fix bug 2023812 / GHSA-8rfp-98v4-mmr6.

  Fix XSS issue with sanitize_uri_value where disallowed schemes with Unicode invisible characters wouldn't be rejected.

  For example::

  import bleach payload1 = 'Click' result1 = bleach.clean(payload1) print(repr(result1))

  outputs::

  'Click'

  See the advisory for details.

• Fix GHSA-gj48-438w-jh9v.

  Fix issue where URI sanitization wasn't happening in formaction attributes.

  See the advisory for details.

Bug fixes

• Add support for pypy 3.11. (#764)

• Drop version max in tinycss2 pin. (#772)

  This removes one of the things we had to keep checking and updating. Users now own the responsibility for correctness with the version of tinycss2 they're using.

• f0355a7 fix: fix last release date in CHANGES
• ae4e8a2 chore: bleach 6.4.0 and final release
• 970df58 fix: uri-sanitization in formaction attributes
• 7c4867c fix: xss bypass in allowed protocol test using unicode invisible characters
• 913ab75 fix: reduce redundancy in workflow jobs
• 218c15a fix: rework pip caching
• 4f0b097 fix: fix tox platform restrictions
• e95a79d chore: update pytest
• 91539d4 Bump actions/cache from 5.0.3 to 5.0.4
• cd47b4c fix: handle left-angle-bracket that's not a tag (#733)
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