Fix the MAVEN_GPG_PASSPHRASE in GH CI workflow

Author: tzolov

.github/workflows/continuous-integration.yml

@@ -28,6 +28,7 @@ jobs:
         env:
           MAVEN_USERNAME: ${{ secrets.OSSRH_USERNAME }}
           MAVEN_PASSWORD: ${{ secrets.OSSRH_TOKEN }}
+          MAVEN_GPG_PASSPHRASE: ${{ secrets.SIGNING_PASSPHRASE }}
         run: |
           mvn -Pjavadoc -Prelease --batch-mode --update-snapshots deploy