update github action - diff-tree

.github/workflows/build_images_uv.yaml

@@ -23,11 +23,11 @@ jobs:
       - name: Check modified paths
         id: modified-paths
         run: |
-          if git diff --name-only ${{ github.event.before }} ${{ github.event.pull_request.head.sha }} | grep -E '^lumigator/|^\.github/'; then
-            echo "Changes detected. Rebuilding image..."
+          if git diff-tree --no-commit-id --name-only -r ${{ github.sha }} | xargs | grep -E '^lumigator/|^\.github/'; then
+            echo "Changes detected, image rebuild required..."
             is_image_build_required=true
           else
-            echo "No relevant changes detected."
+            echo "No relevant changes detected, image rebuild not required."
             is_image_build_required=false
           fi
           echo "is_image_build_required=$is_image_build_required" >> $GITHUB_OUTPUT