Update release workflow

Author: y-a-n-n

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - run: echo ::set-env name=RELEASE_VERSION::${GITHUB_REF:10}
+      - run: echo "RELEASE_VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
       - name: Build
         run: gradle jar
       - name: Create release