GitHub CI Build: Use Maven 3.9.9.

Author: wilx

.github/workflows/maven-ci.yml

@@ -32,7 +32,7 @@ jobs:
     - name: Set up Maven
       uses: stCarolas/setup-maven@d6af6abeda15e98926a57b5aa970a96bb37f97d1 # v5
       with:
-        maven-version: 3.9.7
+        maven-version: 3.9.9
     - name: Check which subproject changed and build affected ones
       uses: dorny/paths-filter@v3
       id: changes