DEV: Remove full group refreshes from tests (#25414)

We have all these calls to Group.refresh_automatic_groups! littered throughout the tests. Including tests that are seemingly unrelated to groups. This is because automatic group memberships aren't fabricated when making a vanilla user. There are two places where you'd want to use this:

You have fabricated a user that needs a certain trust level (which is now based on group membership.)
You need the system user to have a certain trust level.
In the first case, we can pass refresh_auto_groups: true to the fabricator instead. This is a more lightweight operation that only considers a single user, instead of all users in all groups.

The second case is no longer a thing after #25400.

spec/lib/composer_messages_finder_spec.rb

@@ -143,9 +143,7 @@ RSpec.describe ComposerMessagesFinder do
     end
 
     it "doesn't notify users if 'allow_uploaded_avatars' setting is disabled" do
-      user.update!(trust_level: 3)
-      Group.refresh_automatic_groups!
-      user.reload
+      user.change_trust_level!(TrustLevel[3])
 
       SiteSetting.uploaded_avatars_allowed_groups = ""
       expect(finder.check_avatar_notification).to be_blank