add test timeout

Author: KotlinIsland

mypyc/test/test_run.py

@@ -11,7 +11,6 @@
 import subprocess
 import sys
 import time
-from time import sleep
 from typing import Any, Iterator, cast
 
 from mypy import build
@@ -313,16 +312,8 @@ def run_case_step(self, testcase: DataDrivenTestCase, incremental_step: int) ->
             stderr=subprocess.STDOUT,
             env=env,
         )
-        try:
-            proc.wait(timeout=0)
-        except subprocess.TimeoutExpired:
-            print("Timed out")
-            while True:
-                c = proc.stdout.read(1)
-                if c == b"":
-                    break
-                print(c.decode(), end='')
-            raise
+        if sys.version_info() >= (3, 12):
+            proc.wait(timeout=30)
         output = proc.communicate()[0].decode("utf8")
         outlines = output.splitlines()