GLib unit tests fail on macOS runner due to localhost being out of addresses

For a couple of days now, GLib CI runs on macOS have reliably failed with the gsocketclient-slow test failing:

# GLib-GIO-DEBUG: GSocketClient: Starting TCP connection attempt
# GLib-GIO-DEBUG: GSocketClient: Connection attempt failed: Can't assign requested address
# GLib-GIO-DEBUG: GSocketClient: Starting new address enumeration
# GLib-GIO-DEBUG: GSocketClient: Address enumeration completed (out of addresses)
# GLib-GIO-DEBUG: GSocketClient: Address enumeration failed: (null)
# GLib-GIO-DEBUG: GSocketClient: Connection failed: Could not connect to localhost: Can't assign requested address
not ok /socket-client/connection-fail - GLib-GIO:ERROR:../gio/tests/gsocketclient-slow.c:231:test_connection_failed: assertion failed (local_error == (g-io-error-quark, 39)): Could not connect to localhost: Can't assign requested address (g-io-error-quark, 0)
Bail out!

It looks like some process somewhere is hogging all the sockets? Perhaps the CI runner needs to be restarted.