feat: add OVERRIDE_RUNS_ON variables to control runners per repository

Author: puehringer

.github/workflows/build-docker-artifacts.yml

@@ -153,7 +153,7 @@ jobs:
       fail-fast: ${{ inputs.fail_fast }}
       matrix:
         component: ${{ fromJson(needs.get-flavors.outputs.result).components }}
-    runs-on: ${{ inputs.runs_on || 'ubuntu-22.04' }}
+    runs-on: ${{ vars.OVERRIDE_BUILD_DOCKER_ARTIFACTS_RUNS_ON || inputs.runs_on || 'ubuntu-22.04' }}
     steps:
       - name: View flavor and component
         shell: bash