chore: Import GPG key in GitHub Actions workflow for enhanced deployment security

- Added a step to import the GPG key directly from GitHub secrets, improving the security and efficiency of the deployment process.
- This change streamlines the workflow by eliminating unnecessary intermediate steps in GPG key management.

Author: Marvin Zhang

.github/workflows/publish.yml

@@ -44,6 +44,8 @@ jobs:
           server-password: MAVEN_PASSWORD
           gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
           gpg-passphrase: MAVEN_GPG_PASSPHRASE
+      - name: Import GPG key
+        run: echo "${{ secrets.GPG_PRIVATE_KEY }}" | base64 --decode | gpg --import --batch
       - name: Set version
         run: mvn versions:set -DnewVersion=${{ github.event.release.tag_name }}
       - name: Publish package