Test suite raises errors on Python 3.12.0a7

[freakboy3742]

Describe the bug

The gbulb test suite is current raising an error under Python 3.12.0a7. It appears to be due to a change in the argument types accepted by Task().

Steps to reproduce

1. Run the gbulb test suite under Python 3.12.0a7

Expected behavior

Test suite should pass

Screenshots

No response

Environment

• Operating System: Linux
• Python version: 3.12.0a7

Logs

82
==============================================================================
[83](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:84)
ERROR: tests/test_utils.py::test_wait_signal
[84](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:85)
------------------------------------------------------------------------------
[85](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:86)
Traceback (most recent call last):
[86](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:87)
  File "/home/runner/work/gbulb/gbulb/tests/test_utils.py", line 95, in test_wait_signal
[87](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:88)
    glib_loop.create_task(emitter()),
[88](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:89)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[89](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:90)
  File "/opt/hostedtoolcache/Python/3.12.0-alpha.7/x64/lib/python3.12/asyncio/base_events.py", line 436, in create_task
[90](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:91)
    task = tasks.Task(coro, loop=self, name=name, context=context)
[91](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:92)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[92](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:93)
TypeError: a coroutine was expected, got <generator object test_wait_signal.<locals>.emitter at 0x7f5e546a60c0>
[93](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:94)

[94](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:95)
==============================================================================
[95](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:96)
ERROR: tests/test_utils.py::test_wait_signal_cancel
[96](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:97)
------------------------------------------------------------------------------
[97](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:98)
Traceback (most recent call last):
[98](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:99)
  File "/home/runner/work/gbulb/gbulb/tests/test_utils.py", line 143, in test_wait_signal_cancel
[99](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:100)
    glib_loop.create_task(waiter()),
[100](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:101)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[101](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:102)
  File "/opt/hostedtoolcache/Python/3.12.0-alpha.7/x64/lib/python3.12/asyncio/base_events.py", line 436, in create_task
[102](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:103)
    task = tasks.Task(coro, loop=self, name=name, context=context)
[103](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:104)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[104](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:105)
TypeError: a coroutine was expected, got <generator object test_wait_signal_cancel.<locals>.waiter at 0x7f5e546b9000>
[105](https://github.com/beeware/gbulb/actions/runs/4715343264/jobs/8362285070?pr=77#step:6:106)

Additional context

No response