gh-93852: Add test.support.create_unix_domain_name() (#93914)

test_asyncio, test_logging, test_socket and test_socketserver now
create AF_UNIX domains in the current directory to no longer fail
with OSError("AF_UNIX path too long") if the temporary directory (the
TMPDIR environment variable) is too long.

Modify the following tests to use create_unix_domain_name():

* test_asyncio
* test_logging
* test_socket
* test_socketserver

test_asyncio.utils: remove unused time import.