.github/workflows: always ignore go:generate dnsfallback check

Keep the now-redundant github.ref branch check for
the future, in case we want to change the policy for main vs
release-branch again later. Save somebody the YAML debugging
time.

.github/workflows/go_generate.yml

@@ -30,7 +30,7 @@ jobs:
           then
             pkgs=$(go list ./... | grep -v dnsfallback)
           else
-            pkgs=$(go list ./...)
+            pkgs=$(go list ./... | grep -v dnsfallback)
           fi
           go generate $pkgs
           echo