Update ghcr.io/cloudnative-pg/postgresql Docker tag to v18

.gitea/workflows/lint-test.yaml

@@ -92,13 +92,7 @@ jobs:
         id: branch-exists
         if: github.event_name == 'push' || steps.check-branch-exists.outputs.exists == 'true' && github.event_name == 'pull_request'
         run: |
-          if [ ${{ github.event_name == 'push' }} ]; then
-            echo ">> Action is from a push event, will continue with linting"
-
-          else
-            echo ">> Branch ${{ gitea.base_ref }} exists, will continue with linting"
-
-          fi
+          echo ">> Branch ${{ gitea.base_ref }} exists, will continue with linting"
 
           echo "----"
 
@@ -106,7 +100,6 @@ jobs:
 
       - name: Set up Helm
         uses: azure/setup-helm@v4
-        if: steps.branch-exists.outputs.exists == 'true'
         with:
           token: ${{ secrets.GITEA_TOKEN }}
           version: v3
@@ -136,7 +129,7 @@ jobs:
 
             for path in $GIT_DIFF; do
               CHANGED_CHARTS+=$(echo "$path" | awk -F '/' '{print $2}')
-              CHANGED_CHARTS+=$(echo " ")
+              RENDER_DIR+=$(echo " ")
             done
 
           else