* Use `settings.delayed_group_deletion=False` as that is the
   recommended method to turn off the delayed group deletion now.
 * Change test to look for `default` as `pages` is not mentioned in
   the docs[1]

[1] https://docs.gitlab.com/ee/api/sidekiq_metrics.html#get-the-current-queue-metrics

The GitHub CI is showing a ResourceWarning, causing our test to fail.

Update test to only look for our UserWarning which should not appear.

What was seen when debugging the GitHub CI:
{message:
    ResourceWarning(
        "unclosed <socket.socket fd=12, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('127.0.0.1', 50862), raddr=('127.0.0.1', 8080)>"
    ),
    category: 'ResourceWarning',
    filename: '/home/runner/work/python-gitlab/python-gitlab/.tox/api_func_v4/lib/python3.10/site-packages/urllib3/poolmanager.py',
    lineno: 271,
    line: None
}

Make it so can run just the test_gitlab.py functional test.

For example:
$ tox -e api_func_v4 -- -k test_gitlab.py

Catch the deprecation warning for the call to `gl.lint()`, so it won't
show up in the log.