Conditional Timeout() by OS (disable on Windows) (ultralytics#7013)

* Conditional `Timeout()` by OS (disable on Windows)

* Update general.py

utils/general.py

@@ -123,13 +123,15 @@ def _timeout_handler(self, signum, frame):
         raise TimeoutError(self.timeout_message)
 
     def __enter__(self):
-        signal.signal(signal.SIGALRM, self._timeout_handler)  # Set handler for SIGALRM
-        signal.alarm(self.seconds)  # start countdown for SIGALRM to be raised
+        if platform.system() != 'Windows':  # not supported on Windows
+            signal.signal(signal.SIGALRM, self._timeout_handler)  # Set handler for SIGALRM
+            signal.alarm(self.seconds)  # start countdown for SIGALRM to be raised
 
     def __exit__(self, exc_type, exc_val, exc_tb):
-        signal.alarm(0)  # Cancel SIGALRM if it's scheduled
-        if self.suppress and exc_type is TimeoutError:  # Suppress TimeoutError
-            return True
+        if platform.system() != 'Windows':
+            signal.alarm(0)  # Cancel SIGALRM if it's scheduled
+            if self.suppress and exc_type is TimeoutError:  # Suppress TimeoutError
+                return True
 
 
 class WorkingDirectory(contextlib.ContextDecorator):