Fix TSan failure on Darwin.

We could end up logging after Matter stack shutdown and when a different stack
was being configured, which would cause a thread race.

Also fixes a situation where we could try to resubscribe to things after our
MTRDevice has been invalidated.

Fixes #27425

src/darwin/Framework/CHIP/MTRDevice.mm

@@ -237,6 +237,10 @@ - (void)invalidate
 
     _weakDelegate = nil;
 
+    // Make sure we don't try to resubscribe if we have a pending resubscribe
+    // attempt, since we now have no delegate.
+    _reattemptingSubscription = NO;
+
     os_unfair_lock_unlock(&self->_lock);
 }
 
@@ -336,7 +340,8 @@ - (void)_handleSubscriptionReset
     // if there is no delegate then also do not retry
     id<MTRDeviceDelegate> delegate = _weakDelegate.strongObject;
     if (!delegate) {
-        MTR_LOG_DEFAULT("%@ no delegate - do not reattempt subscription", self);
+        // NOTE: Do not log anythig here: we have been invalidated, and the
+        // Matter stack might already be torn down.
         os_unfair_lock_unlock(&self->_lock);
         return;
     }