core, params: define london block at 12965000 (#23176)

* core, params: define london block at 12965000

* core/forkid: fix test

params/config.go

@@ -69,6 +69,7 @@ var (
 		IstanbulBlock:       big.NewInt(9_069_000),
 		MuirGlacierBlock:    big.NewInt(9_200_000),
 		BerlinBlock:         big.NewInt(12_244_000),
+		LondonBlock:         big.NewInt(12_965_000),
 		Ethash:              new(EthashConfig),
 	}