loop: silence W0201 (attribute outside init) in set_status

Silence pylint warning W0201 (attribute-defined-outside-init) in
`set_status`; it sets dynamic attributes on the LoopInfo class
which pylint does not recognize.

osbuild/loop.py

@@ -353,6 +353,7 @@ class Loop:
             unchanged (default is None)
         """
 
+        #  pylint: disable=attribute-defined-outside-init
         info = self.get_status()
         if offset:
             info.lo_offset = offset