Bump actions/cache from v1 to v2.1.2 (#3296)

Bumps [actions/cache](https://github.com/actions/cache) from v1 to v2.1.2.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](https://github.com/actions/cache/compare/v1...d1255ad9362389eac595a9ae406b8e8cb3331f16)

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

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

.github/workflows/maven.yml

@@ -14,7 +14,7 @@ jobs:
     - uses: actions/checkout@v1
 
     - name: Restore dependency cache
-      uses: actions/cache@v1
+      uses: actions/cache@v2.1.2
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}