Change runner to self-hosted for Docker builds

Author: dclong

.github/workflows/build_images_regular.yml

@@ -4,7 +4,7 @@ on:
     - cron: '0 9 13 * *'
 jobs:
   build_docker_images_regularly:
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     permissions:
       issues: write
       pull-requests: write