Incompatibility with Twisted release 25.5.0

[hacklschorsch]

Tahoe-LAFS CI breaks with latest ​Twisted (25.5.0) released on 2025-06-07.

From ​this test run:

  Error: 
  Traceback (most recent call last):
  Failure: testtools.testresult.real._StringException: twisted-log: {{{2025-06-11 01:29:37+0000 [-] Main loop terminated.}}}
  
  Traceback (most recent call last):
    File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py312-coverage/lib/python3.12/site-packages/twisted/internet/defer.py", line 216, in maybeDeferred
      result = f(*args, **kwargs)
               ^^^^^^^^^^^^^^^^^^
    File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py312-coverage/lib/python3.12/site-packages/testtools/testcase.py", line 701, in _run_setup
      ret = self.setUp()
            ^^^^^^^^^^^^
    File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py312-coverage/lib/python3.12/site-packages/allmydata/test/web/test_logs.py", line 75, in setUp
      self.reactor = MemoryReactorClockResolver()
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py312-coverage/lib/python3.12/site-packages/twisted/internet/testing.py", line 835, in __init__
      MemoryReactor.__init__(self)
    File "/home/runner/work/tahoe-lafs/tahoe-lafs/.tox/py312-coverage/lib/python3.12/site-packages/twisted/internet/testing.py", line 569, in __init__
      self.nameResolver = SynchronousResolver()
      ^^^^^^^^^^^^^^^^^
  AttributeError: property 'nameResolver' of 'MemoryReactorClockResolver' object has no setter
  
  
  allmydata.test.web.test_logs.TestStreamingLogs.test_one_log

[meejah]

This can also be fixed in Autobahn