fix(gha): use github actor in image name

Author: jfroy

.github/workflows/image.yaml

@@ -109,7 +109,7 @@ jobs:
 
       - name: Build image
         env:
-          IMAGE_NAME: ghcr.io/nvidia/container-toolkit
+          IMAGE_NAME: ghcr.io/${{ github.actor }}/container-toolkit
           VERSION: ${{ inputs.version }}
           PUSH_ON_BUILD: "true"
           BUILD_MULTI_ARCH_IMAGES: ${{ inputs.build_multi_arch_images }}