Bump actions/cache from 3 to 4 (#107)

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [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/v3...v4)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build-dockers.yml

@@ -41,7 +41,7 @@ jobs:
           commit_user_email: ${{ vars.COMMIT_USER }}
 
       - name: Cache build output
-        uses: actions/cache/save@v3
+        uses: actions/cache/save@v4
         with:
           path: build
           key: build-dockers-${{ github.sha }}
@@ -68,7 +68,7 @@ jobs:
           ref: ${{ github.head_ref }}
 
       - name: Restore build output
-        uses: actions/cache/restore@v3
+        uses: actions/cache/restore@v4
         with:
           path: build
           key: build-dockers-${{ github.sha }}