[fix] function called for migration

migrations/13.0.1.0.0/post-migration.py

@@ -33,4 +33,4 @@ def res_partner_map_values(env):
 
 @openupgrade.migrate()
 def migrate(env, version):
-    ur_month_timesheet_map_values(env)
+    res_partner_map_values(env)