Remove unused imports from conftest.py

Cleaned up the tests/conftest.py file by removing unused imports: signal, socket, subprocess, sys, and time.

Author: JR-1991

tests/conftest.py

@@ -1,10 +1,5 @@
 import os
 import random
-import signal
-import socket
-import subprocess
-import sys
-import time
 from typing import Literal, Tuple, Union, overload
 
 import httpx