Add errno entry to exc_info in core.get_jobs schema (#14077)

A recent change to exc_info dictionary inside core.get_jobs output
was not reflected in the returns decorator schema.

src/middlewared/middlewared/service/core_service.py

@@ -184,6 +184,7 @@ def __job_by_credential_and_id(self, credential, job_id):
             'exc_info',
             Str('repr', null=True),
             Str('type', null=True),
+            Int('errno', null=True),
             Any('extra', null=True),
             null=True
         ),