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](BuildJet/cache@v3...v4)

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

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

.github/workflows/test-integration.yml

@@ -46,7 +46,7 @@ jobs:
           submodules: false
           lfs: false
 
-      - uses: buildjet/cache@v3
+      - uses: buildjet/cache@v4
         with:
           path: Library
           key: Library-${{ matrix.unityVersion }}