Disable setting the `latest` tag for 4.1 docker builds (#27023)

.github/workflows/build-releases.yml

@@ -19,10 +19,8 @@ jobs:
         ghcr.io/mastodon/mastodon
       # Do not use cache when building releases, so apt update is always ran and the release always contain the latest packages
       cache: false
-      # Only tag with latest when ran against the latest stable branch
-      # This needs to be updated after each minor version release
       flavor: |
-        latest=${{ startsWith(github.ref, 'refs/tags/v4.1.') }}
+        latest=false
       tags: |
         type=pep440,pattern={{raw}}
         type=pep440,pattern=v{{major}}.{{minor}}