chore(doc): bump the github-actions group in /doc with 2 updates

Bumps the github-actions group in /doc with 2 updates: [sphinx](https://github.com/sphinx-doc/sphinx) and [sphinx-notfound-page](https://github.com/readthedocs/sphinx-notfound-page).


Updates `sphinx` from 7.3.7 to 8.0.2
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.0.2/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.3.7...v8.0.2)

Updates `sphinx-notfound-page` from 1.0.2 to 1.0.4
- [Changelog](https://github.com/readthedocs/sphinx-notfound-page/blob/main/CHANGELOG.rst)
- [Commits](readthedocs/sphinx-notfound-page@1.0.2...1.0.4)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
- dependency-name: sphinx-notfound-page
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: github-actions
...

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

Author: dependabot[bot]

doc/requirements.txt

@@ -2,5 +2,5 @@ breathe==4.35.0
 exhale==0.3.7
 myst-parser==3.0.1
 myst-parser[linkify]
-sphinx==7.3.7
-sphinx-notfound-page==1.0.2
+sphinx==8.0.2
+sphinx-notfound-page==1.0.4