[cumulus] Improved check for sane bridge fees calculations (#3175)

- [x] change constants when CI fails (should fail :) )

On the AssetHubRococo: 1701175800126 -> 1700929825257 = 0.15 %
decreased.
```
Feb 02 12:59:05.520 ERROR bridges::estimate: `bridging::XcmBridgeHubRouterBaseFee` actual value: 1701175800126 for runtime: statemine-1006000 (statemine-0.tx14.au1)

Feb 02 13:02:40.647 ERROR bridges::estimate: `bridging::XcmBridgeHubRouterBaseFee` actual value: 1700929825257 for runtime: statemine-1006000 (statemine-0.tx14.au1)

```

On the AssetHubWestend: 2116038876326 -> 1641718372993 = 22.4 %
decreased.
```
Feb 02 12:56:00.880 ERROR bridges::estimate: `bridging::XcmBridgeHubRouterBaseFee` actual value: 2116038876326 for runtime: westmint-1006000 (westmint-0.tx14.au1)

Feb 02 13:04:42.515 ERROR bridges::estimate: `bridging::XcmBridgeHubRouterBaseFee` actual value: 1641718372993 for runtime: westmint-1006000 (westmint-0.tx14.au1)
```

(cherry picked from commit 74b597f)

primitives/chain-bridge-hub-rococo/src/lib.rs

@@ -50,7 +50,7 @@ impl Chain for BridgeHubRococo {
 	}
 
 	fn max_extrinsic_weight() -> Weight {
-		BlockWeightsForAsyncBacking::get()
+		BlockWeights::get()
 			.get(DispatchClass::Normal)
 			.max_extrinsic
 			.unwrap_or(Weight::MAX)
@@ -107,5 +107,5 @@ frame_support::parameter_types! {
 
 	/// Transaction fee that is paid at the Rococo BridgeHub for delivering single outbound message confirmation.
 	/// (initially was calculated by test `BridgeHubRococo::can_calculate_fee_for_complex_message_confirmation_transaction` + `33%`)
-	pub const BridgeHubRococoBaseConfirmationFeeInRocs: u128 = 5_380_904_835;
+	pub const BridgeHubRococoBaseConfirmationFeeInRocs: u128 = 5_380_829_647;
 }