Update Build_External_Rock.yaml workflow source

Author: clay-lake

.github/workflows/Build_External_Rock.yaml

@@ -9,10 +9,10 @@ on:
 
 jobs:
     build:
-        uses: clay-lake/oci-factory/.github/workflows/Build-Rock.yaml@refactor-workflows
+        uses: canonical/oci-factory/.github/workflows/Build-Rock.yaml@ROCKS-1452/oci-factory-refactor-build-rock-to-be-externally-reusable
         with:
             oci-archive-name: "external_mock-rock"
             rock-repo: clay-lake/mock-rock
             rock-repo-commit: main
             rockfile-directory: /mock-rock/1.1/
-            arch-map: '{"amd64": "ubuntu-22.04"}'
+            arch-map: '{"amd64": "ubuntu-22.04"}'