ci: replace deprecated use of set-output

Author: cicirello

.github/workflows/maven-publish.yml

@@ -17,7 +17,7 @@ jobs:
 
     - name: Get the release version
       id: get_version
-      run: echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\/v/}
+      run: echo "VERSION=${GITHUB_REF/refs\/tags\/v/}" >> $GITHUB_OUTPUT
 
     - name: Set up JDK 11 for deploy to OSSRH
       uses: actions/setup-java@v3