chore(deps): bump actions/cache from 4 to 5 in the actions group

Bumps the actions group with 1 update: [actions/cache](https://github.com/actions/cache).


Updates `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](actions/cache@v4...v5)

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

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

Author: dependabot[bot]

.github/workflows/check-external-links.yml

@@ -17,7 +17,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Restore lychee cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .lycheecache
           key: cache-lychee-${{ hashFiles('lychee.toml') }}