Integration tests fail under pytest 8.0.x

[nsoranzo]

The integration tests fail when using pytest 8.0.x (noticed in the "Update Python dependencies" pull requests), which means we cannot update it in our dev requirements.
The errors starts after some test modules succeeded, and look like this:

_____ ERROR at setup of TestConfigSchema.test_schema_path_resolution_graph _____

cls = <class 'integration.test_config_schema.TestConfigSchema'>

    @classmethod
    def setup_class(cls):
>       cls.setUpClass()

lib/galaxy/util/unittest.py:19: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
lib/galaxy_test/driver/integration_util.py:123: in setUpClass
    cls._test_driver.setup(config_object=cls)
lib/galaxy_test/driver/driver_util.py:914: in setup
    self._register_and_run_servers(config_object)
lib/galaxy_test/driver/driver_util.py:969: in _register_and_run_servers
    server_wrapper = launch_server(
lib/galaxy_test/driver/driver_util.py:781: in launch_server
    port = attempt_ports(port)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

port = '8148', set_galaxy_web_port = True

    def attempt_ports(port=None, set_galaxy_web_port=True) -> str:
        if port is not None:
            if not attempt_port(int(port)):
>               raise Exception(f"An existing process seems bound to specified test server port [{port}]")
E               Exception: An existing process seems bound to specified test server port [8148]

lib/galaxy_test/driver/driver_util.py:496: Exception

Originally posted by @nsoranzo in #17420 (comment)

I have bisected the changes between pytest 7.4.4 and 8.0.0, which pointed to pytest-dev/pytest@385796b as the commit introducing the issue.

I don't really have an idea why this is happening and what's the connection with that pytest commit, help appreciated!