GM: disable checks on loopback bus (#26015)

* disabling checks on loopback bus

* Apply suggestions from code review

Co-authored-by: Shane Smiskol <shane@smiskol.com>
old-commit-hash: ac88ad871a

selfdrive/car/gm/carstate.py

@@ -177,9 +177,7 @@ class CarState(CarStateBase):
     ]
 
     checks = [
-      ("ASCMLKASteeringCmd", 10), # 10 Hz is the stock inactive rate (every 100ms).
-      #                             While active 50 Hz (every 20 ms) is normal
-      #                             EPS will tolerate around 200ms when active before faulting
+      ("ASCMLKASteeringCmd", 0),
     ]
 
-    return CANParser(DBC[CP.carFingerprint]["pt"], signals, checks, CanBus.LOOPBACK)
+    return CANParser(DBC[CP.carFingerprint]["pt"], signals, checks, CanBus.LOOPBACK, enforce_checks=False)