update maven snapshot config

Author: efranqueiro

.github/workflows/snapshot.yml

@@ -21,8 +21,11 @@ jobs:
         server-id: sonatype-nexus-staging
         server-username: MAVEN_USERNAME
         server-password: MAVEN_PASSWORD
+        gpg-private-key: ${{ secrets.CENTRAL_GPG_SECRET_KEY }}
+        gpg-passphrase: GPG_PASSPHRASE
     - name: Publish to Maven
       run: mvn -ntp -B --fail-at-end -Dmaven.test.skip=true clean deploy
       env:
         MAVEN_USERNAME: ${{ secrets.CENTRAL_USERNAME }}
         MAVEN_PASSWORD: ${{ secrets.CENTRAL_PASSWORD }}
+        GPG_PASSPHRASE: ${{ secrets.CENTRAL_GPG_SECRET_KEY_PASSWORD }}