build(deps): bump lightning-utilities in /requirements

Bumps [lightning-utilities](https://github.com/Lightning-AI/utilities) from 0.11.7 to 0.11.8.
- [Release notes](https://github.com/Lightning-AI/utilities/releases)
- [Changelog](https://github.com/Lightning-AI/utilities/blob/main/CHANGELOG.md)
- [Commits](Lightning-AI/utilities@v0.11.7...v0.11.8)

---
updated-dependencies:
- dependency-name: lightning-utilities
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements/_docs.txt

@@ -13,7 +13,7 @@ sphinx-autobuild ==2024.10.3
 sphinx-gallery ==0.18.0
 
 lightning >=1.8.0, <2.5.0
-lightning-utilities ==0.11.7
+lightning-utilities ==0.11.8
 pydantic > 1.0.0, < 3.0.0
 
 # integrations