eth/catalyst: allow getPayloadV2 for pre-shanghai payloads (#33932)

I observed failing tests in Hive `engine-withdrawals`:

-
https://hive.ethpandaops.io/#/test/generic/1772351960-ad3e3e460605c670efe1b4f4178eb422?testnumber=146
-
https://hive.ethpandaops.io/#/test/generic/1772351960-ad3e3e460605c670efe1b4f4178eb422?testnumber=147

```shell
  DEBUG (Withdrawals Fork on Block 2): NextPayloadID before getPayloadV2:
  id=0x01487547e54e8abe version=1
  >> engine_getPayloadV2("0x01487547e54e8abe")
  << error: {"code":-38005,"message":"Unsupported fork"}
  FAIL: Expected no error on EngineGetPayloadV2: error=Unsupported fork
```
 
The same failure pattern occurred for Block 3.

Per Shanghai engine_getPayloadV2 spec, pre-Shanghai payloads should be
accepted via V2 and returned as ExecutionPayloadV1:
- executionPayload: ExecutionPayloadV1 | ExecutionPayloadV2
- ExecutionPayloadV1 MUST be returned if payload timestamp < Shanghai
timestamp
- ExecutionPayloadV2 MUST be returned if payload timestamp >= Shanghai
timestamp

Reference:
-
https://github.com/ethereum/execution-apis/blob/main/src/engine/shanghai.md#engine_getpayloadv2

Current implementation only allows GetPayloadV2 on the Shanghai fork
window (`[]forks.Fork{forks.Shanghai}`), so pre-Shanghai payloads are
rejected with Unsupported fork.

If my interpretation of the spec is incorrect, please let me know and I
can adjust accordingly.

---------

Co-authored-by: muzry.li <muzry.li1@ambergroup.io>

eth/catalyst/api.go

@@ -435,7 +435,7 @@ func (api *ConsensusAPI) GetPayloadV2(payloadID engine.PayloadID) (*engine.Execu
 		payloadID,
 		false,
 		[]engine.PayloadVersion{engine.PayloadV1, engine.PayloadV2},
-		[]forks.Fork{forks.Shanghai},
+		[]forks.Fork{forks.Paris, forks.Shanghai},
 	)
 }
 

eth/catalyst/api_test.go

@@ -1219,6 +1219,11 @@ func TestNilWithdrawals(t *testing.T) {
 			Random:       test.blockParams.Random,
 			Version:      payloadVersion,
 		}).Id()
+		if !shanghai {
+			if _, err := api.GetPayloadV2(payloadID); err != nil {
+				t.Fatalf("GetPayloadV2 rejected pre-shanghai payload: %v", err)
+			}
+		}
 		execData, err := api.getPayload(payloadID, false, nil, nil)
 		if err != nil {
 			t.Fatalf("error getting payload, err=%v", err)