Turn the CI green before the next release

[felixdivo]

Most of the work was done in #1224 and #1221, but maybe small stuff is left and we want to have a clean release.

[zariiii9003]

There are also some deprecation warnings that we could fix

can/interfaces/__init__.py:36
  /home/runner/work/python-can/python-can/can/interfaces/__init__.py:36: DeprecationWarning: SelectableGroups dict interface is deprecated. Use select.
    if "can.interface" in entry:

test/notifier_test.py::AsyncNotifierTest::test_asyncio_notifier
  /home/runner/work/python-can/python-can/test/notifier_test.py:43: DeprecationWarning: There is no current event loop
    loop = asyncio.get_event_loop()

[felixdivo]

Since c7ba84a, this should be done.