ci: add pr number to the cache key (#12764)

Signed-off-by: Nelesh Singla <[email protected]>

Author: nsingla

.github/workflows/image-builds-with-cache.yml

@@ -93,7 +93,7 @@ jobs:
         uses: actions/cache@v5
         with:
           path: .build-marker-${{ matrix.image }}
-          key: image-built-${{ matrix.image }}-${{ github.sha }}-${{ steps.date.outputs.date }}
+          key: image-built-${{ matrix.image }}-${{ github.sha }}-${{ github.event.pull_request.number || github.ref_name }}-${{ steps.date.outputs.date }}
           lookup-only: true
 
       - name: Set up Docker Buildx
@@ -142,4 +142,4 @@ jobs:
         uses: actions/cache/save@v5
         with:
           path: .build-marker-${{ matrix.image }}
-          key: image-built-${{ matrix.image }}-${{ github.sha }}-${{ steps.date.outputs.date }}
+          key: image-built-${{ matrix.image }}-${{ github.sha }}-${{ github.event.pull_request.number || github.ref_name }}-${{ steps.date.outputs.date }}