Apply suggestions from code review

Author: solvaholic

.github/workflows/docker.yml

@@ -11,7 +11,6 @@ on:
     # Publish `master` as Docker `latest` image.
     branches:
       - master
-      - version2
 
     # Publish `vX.Y.Z` tags as releases.
     tags:
@@ -25,7 +24,6 @@ on:
       - .github/workflows/docker.yml
     branches:
       - master
-      - version2
     tags:
       - v[12].[0-9]+.[0-9]+