ci: fix git add

We have no subdirs with pom files, so remove this. Otherwise CI stumbles over it.

.github/workflows/release-manual.yml

@@ -32,13 +32,13 @@ jobs:
       - name: Update version in pom.xml and tag
         run: | 
           mvn -B versions:set -DnewVersion="${{ inputs.version }}" -DgenerateBackupPoms=false
-          git add pom.xml */pom.xml
+          git add pom.xml
           git commit -m "[github-action] Release version ${{ inputs.version }}"
           git tag "${{ inputs.version }}"
       - name: Increment to next version, commit and push
         run: |
           mvn -B versions:set -DnextSnapshot -DnextSnapshotIndexToIncrement=2 -DgenerateBackupPoms=false
-          git add pom.xml */pom.xml
+          git add pom.xml
           git commit -m "[github-action] Increment version after release of ${{ inputs.version }}"
           git push --tags origin main