Fix incorrect/outdated type annotation

This type annotation caused some tests to freeze indefinitely when
upgrading from Twisted 20 to 23.8.  The correct location for `Failure`
is in the module `twisted.python.failure`, but it may have been
incidentally available also in `twisted.internet.defer.failure` in
earlier versions.

Author: lunkwill42

python/nav/mibs/mibretriever.py

@@ -37,6 +37,7 @@
 from twisted.internet import defer, reactor
 from twisted.internet.defer import returnValue
 from twisted.internet.error import TimeoutError
+from twisted.python.failure import Failure
 
 from nav.Snmp import safestring
 from nav.ipdevpoll import ContextLogger
@@ -428,7 +429,7 @@ def _result_formatter(result):
 
             return formatted_result
 
-        def _snmp_timeout_handler(failure: defer.failure.Failure):
+        def _snmp_timeout_handler(failure: Failure):
             """Transforms SnmpTimeoutErrors into "regular" TimeoutErrors"""
             failure.trap(SnmpTimeoutError)
             raise TimeoutError(failure.value)