ci: fix .github/workflows/validate_kong_image_trigger_via_label.yaml workflow (#7816)

Author: pmalek

.github/workflows/validate_kong_image_trigger_via_label.yaml

@@ -64,7 +64,7 @@ jobs:
           BODY: ${{ github.event.issue.body }}
         # Fail the job if we cannot get "### Container image" keyword from issue body.
         run: |
-          kong_container_image=$(echo ${{ env.BODY }} | grep -A 2 '### Container image' | tail -n 1) && \
+          kong_container_image=$(echo "${{ env.BODY }}" | grep -A 2 '### Container image' | tail -n 1) && \
           echo "TEST_KONG_CONTAINER_IMAGE=${kong_container_image}" >> $GITHUB_ENV
       
       # Split the container into repo and tag by ":" and then extract the first 3 segments of tags as its version.