Add GraalVM setup for Java 21

Author: faermanj

.github/workflows/on-tag-release.yaml

@@ -9,6 +9,12 @@ jobs:
   build-and-release:
     runs-on: ubuntu-latest
     steps:
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: '21'
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Checkout code
         uses: actions/checkout@v2