FIX Remove write from SearchableDropdownTrait

In the SearchableDropdownTrait::saveInto method, if the field is a has_one relationship, $record->write() was called. FormField and any other instances of saveInto should not call write - that should be called by the form itself.

src/Forms/SearchableDropdownTrait.php

@@ -397,7 +397,6 @@ public function saveInto(DataObjectInterface $record): void
                     $record->$classNameField = $ids ? $record->ClassName : '';
                 }
             }
-            $record->write();
         } else {
             // has_many / many_many field
             if (!method_exists($record, 'hasMethod')) {