Make sure to do our BLE callbacks on the right dispatch queue. (#20235)

We were calling back into the Matter core while running on the BLE queue.

#20230

src/platform/Darwin/BleConnectionDelegateImpl.mm

@@ -108,7 +108,7 @@ - (id)initWithDiscriminator:(uint16_t)deviceDiscriminator
 
         dispatch_source_set_event_handler(_timer, ^{
             [self stop];
-            _onConnectionError(_appState, BLE_ERROR_APP_CLOSED_CONNECTION);
+            [self dispatchConnectionError:BLE_ERROR_APP_CLOSED_CONNECTION];
         });
         dispatch_source_set_timer(
             _timer, dispatch_walltime(nullptr, kScanningTimeoutInSeconds * NSEC_PER_SEC), DISPATCH_TIME_FOREVER, 5 * NSEC_PER_SEC);
@@ -117,6 +117,21 @@ - (id)initWithDiscriminator:(uint16_t)deviceDiscriminator
     return self;
 }
 
+// All our callback dispatch must happen on _chipWorkQueue
+- (void)dispatchConnectionError:(CHIP_ERROR)error
+{
+    dispatch_async(_chipWorkQueue, ^{
+        self.onConnectionError(self.appState, error);
+    });
+}
+
+- (void)dispatchConnectionComplete:(CBPeripheral *)peripheral
+{
+    dispatch_async(_chipWorkQueue, ^{
+        self.onConnectionComplete(self.appState, (__bridge void *) peripheral);
+    });
+}
+
 // Start CBCentralManagerDelegate
 
 - (void)centralManagerDidUpdateState:(CBCentralManager *)central
@@ -129,7 +144,7 @@ - (void)centralManagerDidUpdateState:(CBCentralManager *)central
     case CBManagerStatePoweredOff:
         ChipLogDetail(Ble, "CBManagerState: OFF");
         [self stop];
-        _onConnectionError(_appState, BLE_ERROR_APP_CLOSED_CONNECTION);
+        [self dispatchConnectionError:BLE_ERROR_APP_CLOSED_CONNECTION];
         break;
     case CBManagerStateUnauthorized:
         ChipLogDetail(Ble, "CBManagerState: Unauthorized");
@@ -216,7 +231,7 @@ - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)err
 
     if (!self.found || error != nil) {
         ChipLogError(Ble, "Service not found on the device.");
-        _onConnectionError(_appState, CHIP_ERROR_INCORRECT_STATE);
+        [self dispatchConnectionError:CHIP_ERROR_INCORRECT_STATE];
     }
 }
 
@@ -228,7 +243,7 @@ - (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForServi
     }
 
     // XXX error ?
-    _onConnectionComplete(_appState, (__bridge void *) peripheral);
+    [self dispatchConnectionComplete:peripheral];
 }
 
 - (void)peripheral:(CBPeripheral *)peripheral