Fix weekly on 6.3

Author: theo-at-unity

.yamato/_abv.yml

@@ -12,7 +12,7 @@ graphics_repo_nightly_6000.3:
         UTR_VERSION: "current"
     triggers:
         recurring:
-          -  branch: master
+          -  branch: 6000.3/staging
              frequency: weekly
     dependencies:
       -  path: .yamato/_templates.yml#all_template_ci_6000.3