⬆ Bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/build-docs.yml

@@ -91,7 +91,7 @@ jobs:
         run: uv sync --locked --no-dev --group docs
       - name: Update Languages
         run: uv run ./scripts/docs.py update-languages
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           key: mkdocs-cards-${{ matrix.lang }}-${{ github.ref }}
           path: docs/${{ matrix.lang }}/.cache