Build(deps): Bump buildjet/cache from 3 to 4

Bumps [buildjet/cache](https://github.com/buildjet/cache) from 3 to 4.
- [Changelog](https://github.com/BuildJet/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/buildjet/cache/compare/v3...v4)

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

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

.github/workflows/floccus.yml

@@ -66,7 +66,7 @@ jobs:
           npm run build-release --if-present
 
       - name: Save context
-        uses: buildjet/cache/save@v3
+        uses: buildjet/cache/save@v4
         with:
           key: floccus-context-${{ matrix.floccus-branch }}-${{ github.run_id }}
           path: ./
@@ -151,7 +151,7 @@ jobs:
         run: npm i -g npm@"${{ matrix.npm-version }}"
 
       - name: Restore context
-        uses: buildjet/cache/restore@v3
+        uses: buildjet/cache/restore@v4
         with:
           fail-on-cache-miss: true
           key: floccus-context-${{matrix.floccus-branch}}-${{ github.run_id }}