[fenix] For https://github.com/mozilla-mobile/fenix/issues/26844: Enable trailing commas rules.

.editorconfig

@@ -1,4 +1,8 @@
 [*.{kt,kts}]
 # Disabling rules that were added in the latest versions of ktlint
 # tracking here: https://github.com/mozilla-mobile/fenix/issues/4861
-ktlint_disabled_rules=import-ordering
+
+ktlint_disabled_rules=import-ordering
+
+ij_kotlin_allow_trailing_comma_on_call_site=true
+ij_kotlin_allow_trailing_comma=true