Bump the llvm-docs-requirements group in /llvm/docs with 3 updates

Bumps the llvm-docs-requirements group in /llvm/docs with 3 updates: [charset-normalizer](https://github.com/Ousret/charset_normalizer), [markupsafe](https://github.com/pallets/markupsafe) and [sphinx](https://github.com/sphinx-doc/sphinx).


Updates `charset-normalizer` from 3.3.2 to 3.4.0
- [Release notes](https://github.com/Ousret/charset_normalizer/releases)
- [Changelog](https://github.com/jawah/charset_normalizer/blob/master/CHANGELOG.md)
- [Commits](jawah/charset_normalizer@3.3.2...3.4.0)

Updates `markupsafe` from 2.1.5 to 3.0.2
- [Release notes](https://github.com/pallets/markupsafe/releases)
- [Changelog](https://github.com/pallets/markupsafe/blob/main/CHANGES.rst)
- [Commits](pallets/markupsafe@2.1.5...3.0.2)

Updates `sphinx` from 8.0.2 to 8.1.3
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.1.3/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.0.2...v8.1.3)

---
updated-dependencies:
- dependency-name: charset-normalizer
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: llvm-docs-requirements
- dependency-name: markupsafe
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: llvm-docs-requirements
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: llvm-docs-requirements
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]