Fix some test warnings

[wookie184]

Currently these warnings are raised when running tests:

tests/bot/exts/backend/test_logging.py::LoggingTests::test_debug_mode_false
tests/bot/exts/backend/test_logging.py::LoggingTests::test_debug_mode_true
  C:\Users\wookie\Documents\GitHub\bot\bot\exts\backend\logging.py:18: RuntimeWarning: coroutine 'Logging.startup_greeting' was never awaited
    scheduling.create_task(self.startup_greeting(), event_loop=self.bot.loop)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/bot/exts/moderation/test_incidents.py: 27 warnings
  C:\Users\wookie\Documents\GitHub\bot\bot\exts\moderation\incidents.py:322: RuntimeWarning: coroutine 'Incidents.fetch_webhook' was never awaited
    scheduling.create_task(self.fetch_webhook(), event_loop=self.bot.loop)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/bot/exts/moderation/test_incidents.py: 27 warnings
  C:\Users\wookie\Documents\GitHub\bot\bot\exts\moderation\incidents.py:325: RuntimeWarning: coroutine 'Incidents.crawl_incidents' was never awaited
    self.crawl_task = scheduling.create_task(self.crawl_incidents(), event_loop=self.bot.loop)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/bot/exts/moderation/test_incidents.py::TestMakeConfirmationTask::test_make_confirmation_task_check
  C:\Users\wookie\Documents\GitHub\bot\tests\bot\exts\moderation\test_incidents.py:461: RuntimeWarning: coroutine 'AsyncMockMixin._execute_mock_call' was never awaited
    self.cog_instance.make_confirmation_task(MockMessage(id=123))
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

This fixes that by patching create_task to just close the coroutine in these places.

I also removed some unnecessary bot.loop arguments to create_task.

[Xithrius]

Perfection