Try a different tutorial (#27)

Using https://medium.com/@jtbsorensen/publish-your-artifact-to-the-maven-central-repository-using-github-actions-15d3b5d9ce88 let's eliminate the settings.xml file, which doesn't seem to work, and try the config values again

.github/workflows/publish.yml

@@ -27,6 +27,9 @@ jobs:
       with:
         distribution: 'temurin'
         java-version: 21
+        server-id: central
+        server-username: MAVEN_USERNAME
+        server-password: MAVEN_PASSWORD
 
     - name: Verify with Maven
       if: github.event_name == 'pull_request'
@@ -59,4 +62,6 @@ jobs:
       run: mvn -B -PsonatypeDeploy deploy -Dserver.username="${{ secrets.MAVEN_USERNAME }}" -Dserver.password="${{ secrets.MAVEN_CENTRAL_TOKEN }}"
       env:
         MAVEN_GPG_PASSPHRASE: ${{ secrets.MAVEN_GPG_PASSPHRASE }}
-        MAVEN_GPG_KEY: ${{ secrets.GPG_SIGNING_KEY }}
+        MAVEN_GPG_KEY: ${{ secrets.GPG_SIGNING_KEY }}
+        MAVEN_USERNAME: ${{ secrets.MAVEN_USERNAME }}
+        MAVEN_PASSWORD: ${{ secrets.MAVEN_CENTRAL_TOKEN }}