ci: fix unquoted expression in images-dev shell condition

Signed-off-by: Immanuel Tikhonov <pchpr.00@list.ru>

Author: immanuwell

.github/workflows/images-dev.yaml

@@ -31,7 +31,7 @@ jobs:
       - name: Getting image tag
         id: tag
         run: |
-          if [ ${{ github.event.pull_request.head.sha }} != "" ]; then
+          if [ "${{ github.event.pull_request.head.sha }}" != "" ]; then
             echo "tag=${{ github.event.pull_request.head.sha }}" >> $GITHUB_OUTPUT
             echo "repo_tags=quay.io/${{ github.repository_owner }}/cilium-cli-ci:${{ github.event.pull_request.head.sha }}" >> $GITHUB_OUTPUT
           else