params: enable osaka fork in MergedTestChainConfig (ethereum#31993)

Author: fjl

params/config.go

@@ -296,14 +296,15 @@ var (
 		ShanghaiTime:            newUint64(0),
 		CancunTime:              newUint64(0),
 		PragueTime:              newUint64(0),
-		OsakaTime:               nil,
+		OsakaTime:               newUint64(0),
 		VerkleTime:              nil,
 		TerminalTotalDifficulty: big.NewInt(0),
 		Ethash:                  new(EthashConfig),
 		Clique:                  nil,
 		BlobScheduleConfig: &BlobScheduleConfig{
 			Cancun: DefaultCancunBlobConfig,
 			Prague: DefaultPragueBlobConfig,
+			Osaka:  DefaultOsakaBlobConfig,
 		},
 	}