DEV: Ignore renames when diffing theme changes

Renamed assets are quite noisy when checking whether a remote theme has local changes.

lib/theme_store/git_importer.rb

@@ -40,7 +40,7 @@ class ThemeStore::GitImporter
       Discourse::Utils.execute_command("git", "checkout", "about.json")
       # adding and diffing on staged so that we catch uploads
       Discourse::Utils.execute_command("git", "add", "-A")
-      return Discourse::Utils.execute_command("git", "diff", "--staged")
+      return Discourse::Utils.execute_command("git", "diff", "--staged", "--no-renames")
     end
   ensure
     FileUtils.rm_rf local_temp_folder if local_temp_folder

spec/models/remote_theme_spec.rb

@@ -170,6 +170,7 @@ describe RemoteTheme do
       @theme.save
       @theme.reload
 
+      expect(remote.diff_local_changes[:diff]).not_to include("similarity index 100%")
       expect(remote.diff_local_changes[:diff]).to include("background-color: blue")
     end
   end