Use shutil instead of os.rename

funkwhale_api/common/utils.py

 import os
+import shutil
 
 
 def rename_file(instance, field_name, new_name, allow_missing_file=False):
@@ -7,7 +8,7 @@ def rename_file(instance, field_name, new_name, allow_missing_file=False):
 
     new_name_with_extension = '{}{}'.format(new_name, extension)
     try:
-        os.rename(field.path, new_name_with_extension)
+        shutil.move(field.path, new_name_with_extension)
     except FileNotFoundError:
         if not allow_missing_file:
             raise