ci: +questing -plucky and dry-run fix for localectl

[dbungert]

Update CI to run on questing instead of plucky.

Doing so produced many failures in the answers integration tests, like so:

Exception ignored in: <function BaseSubprocessTransport.__del__ at 0x788856adf600>
Traceback (most recent call last):
  File "/usr/lib/python3.13/asyncio/base_subprocess.py", line 130, in __del__
    self.close()
  File "/usr/lib/python3.13/asyncio/base_subprocess.py", line 107, in close
    proto.pipe.close()
  File "/usr/lib/python3.13/asyncio/unix_events.py", line 603, in close
    self._close(None)
  File "/usr/lib/python3.13/asyncio/unix_events.py", line 627, in _close
    self._loop.call_soon(self._call_connection_lost, exc)
  File "/usr/lib/python3.13/asyncio/base_events.py", line 827, in call_soon
    self._check_closed()
  File "/usr/lib/python3.13/asyncio/base_events.py", line 550, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

After modifying BaseSubprocessTransport to dump info on the subprocesses being cleaned up, I found that localectl is run in dry-run cases, so let's not do that.