Add Maven server credentials to workflow

Pass Maven server credentials to the setup-java step so the Publish package step can authenticate. Adds server-id 'ossrh' and maps server-username/server-password to MAVEN_USERNAME and MAVEN_PASSWORD (expected as repo secrets) for publishing to OSSRH.

Author: mercyblitz

.github/workflows/maven-publish.yml

@@ -40,6 +40,9 @@ jobs:
         with:
           java-version: '11'
           distribution: 'temurin'
+          server-id: ossrh
+          server-username: MAVEN_USERNAME
+          server-password: MAVEN_PASSWORD
 
       - name: Publish package
         run: ./mvnw