Bump the llvm-docs-requirements group in /llvm/docs with 6 updates

Bumps the llvm-docs-requirements group in /llvm/docs with 6 updates:

| Package | From | To |
| --- | --- | --- |
| [sphinx](https://github.com/sphinx-doc/sphinx) | `8.1.3` | `9.1.0` |
| [docutils](https://github.com/rtfd/recommonmark) | `0.21.2` | `0.22.4` |
| [sphinx-automodapi](https://github.com/astropy/sphinx-automodapi) | `0.20.0` | `0.22.0` |
| [sphinx-reredirects](https://github.com/documatt/sphinx-reredirects) | `0.1.6` | `1.1.0` |
| [furo](https://github.com/pradyunsg/furo) | `2025.7.19` | `2025.12.19` |
| [myst-parser](https://github.com/executablebooks/MyST-Parser) | `4.0.0` | `5.0.0` |


Updates `sphinx` from 8.1.3 to 9.1.0
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v8.1.3...v9.1.0)

Updates `docutils` from 0.21.2 to 0.22.4
- [Changelog](https://github.com/readthedocs/recommonmark/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rtfd/recommonmark/commits)

Updates `sphinx-automodapi` from 0.20.0 to 0.22.0
- [Release notes](https://github.com/astropy/sphinx-automodapi/releases)
- [Changelog](https://github.com/astropy/sphinx-automodapi/blob/main/CHANGES.rst)
- [Commits](astropy/sphinx-automodapi@v0.20.0...v0.22.0)

Updates `sphinx-reredirects` from 0.1.6 to 1.1.0
- [Changelog](https://github.com/documatt/sphinx-reredirects/blob/main/docs/changelog.rst)
- [Commits](documatt/sphinx-reredirects@v0.1.6...v1.1.0)

Updates `furo` from 2025.7.19 to 2025.12.19
- [Release notes](https://github.com/pradyunsg/furo/releases)
- [Changelog](https://github.com/pradyunsg/furo/blob/main/docs/changelog.md)
- [Commits](pradyunsg/furo@2025.07.19...2025.12.19)

Updates `myst-parser` from 4.0.0 to 5.0.0
- [Release notes](https://github.com/executablebooks/MyST-Parser/releases)
- [Changelog](https://github.com/executablebooks/MyST-Parser/blob/master/CHANGELOG.md)
- [Commits](executablebooks/MyST-Parser@v4.0.0...v5.0.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-version: 9.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: llvm-docs-requirements
- dependency-name: docutils
  dependency-version: 0.22.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: llvm-docs-requirements
- dependency-name: sphinx-automodapi
  dependency-version: 0.22.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: llvm-docs-requirements
- dependency-name: sphinx-reredirects
  dependency-version: 1.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: llvm-docs-requirements
- dependency-name: furo
  dependency-version: 2025.12.19
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: llvm-docs-requirements
- dependency-name: myst-parser
  dependency-version: 5.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: llvm-docs-requirements
...

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

Author: dependabot[bot]

llvm/docs/requirements.txt

@@ -1,10 +1,10 @@
-sphinx==8.1.3
-docutils==0.21.2
+sphinx==9.1.0
+docutils==0.22.4
 sphinx-markdown-tables==0.0.17
 recommonmark==0.7.1
-sphinx-automodapi==0.20.0
+sphinx-automodapi==0.22.0
 sphinx-bootstrap-theme==0.8.1
 sphinxcontrib-applehelp==2.0.0
-sphinx-reredirects==0.1.6
-furo==2025.7.19
-myst-parser==4.0.0
+sphinx-reredirects==1.1.0
+furo==2025.12.19
+myst-parser==5.0.0