params, core/forkid: enable cancun on sepolia and holesky (#28834)

This change enables Cancun 

- Sepolia at 1706655072 (Jan 31st, 2024)
- Holesky at 1707305664 (Feb 7th, 2024)

Specification: https://github.com/ethereum/execution-specs/pull/860

core/forkid/forkid_test.go

@@ -106,7 +106,10 @@ func TestCreation(t *testing.T) {
 				{1735370, 0, ID{Hash: checksumToBytes(0xfe3366e7), Next: 1735371}},             // Last London block
 				{1735371, 0, ID{Hash: checksumToBytes(0xb96cbd13), Next: 1677557088}},          // First MergeNetsplit block
 				{1735372, 1677557087, ID{Hash: checksumToBytes(0xb96cbd13), Next: 1677557088}}, // Last MergeNetsplit block
-				{1735372, 1677557088, ID{Hash: checksumToBytes(0xf7f9bc08), Next: 0}},          // First Shanghai block
+				{1735372, 1677557088, ID{Hash: checksumToBytes(0xf7f9bc08), Next: 1706655072}}, // First Shanghai block
+				{1735372, 1706655071, ID{Hash: checksumToBytes(0xf7f9bc08), Next: 1706655072}}, // Last Shanghai block
+				{1735372, 1706655072, ID{Hash: checksumToBytes(0x88cf81d9), Next: 0}},          // First Cancun block
+				{1735372, 2706655072, ID{Hash: checksumToBytes(0x88cf81d9), Next: 0}},          // Future Cancun block
 			},
 		},
 		// Holesky test cases
@@ -114,9 +117,12 @@ func TestCreation(t *testing.T) {
 			params.HoleskyChainConfig,
 			core.DefaultHoleskyGenesisBlock().ToBlock(),
 			[]testcase{
-				{0, 0, ID{Hash: checksumToBytes(0xc61a6098), Next: 1696000704}},   // Unsynced, last Frontier, Homestead, Tangerine, Spurious, Byzantium, Constantinople, Petersburg, Istanbul, Berlin, London, Paris block
-				{123, 0, ID{Hash: checksumToBytes(0xc61a6098), Next: 1696000704}}, // First MergeNetsplit block
-				{123, 1696000704, ID{Hash: checksumToBytes(0xfd4f016b), Next: 0}}, // Last MergeNetsplit block
+				{0, 0, ID{Hash: checksumToBytes(0xc61a6098), Next: 1696000704}},            // Unsynced, last Frontier, Homestead, Tangerine, Spurious, Byzantium, Constantinople, Petersburg, Istanbul, Berlin, London, Paris block
+				{123, 0, ID{Hash: checksumToBytes(0xc61a6098), Next: 1696000704}},          // First MergeNetsplit block
+				{123, 1696000704, ID{Hash: checksumToBytes(0xfd4f016b), Next: 1707305664}}, // First Shanghai block
+				{123, 1707305663, ID{Hash: checksumToBytes(0xfd4f016b), Next: 1707305664}}, // Last Shanghai block
+				{123, 1707305664, ID{Hash: checksumToBytes(0x9b192ad0), Next: 0}},          // First Cancun block
+				{123, 2707305664, ID{Hash: checksumToBytes(0x9b192ad0), Next: 0}},          // Future Cancun block
 			},
 		},
 	}

params/config.go

@@ -81,6 +81,7 @@ var (
 		TerminalTotalDifficultyPassed: true,
 		MergeNetsplitBlock:            nil,
 		ShanghaiTime:                  newUint64(1696000704),
+		CancunTime:                    newUint64(1707305664),
 		Ethash:                        new(EthashConfig),
 	}
 	// SepoliaChainConfig contains the chain parameters to run a node on the Sepolia test network.
@@ -105,6 +106,7 @@ var (
 		TerminalTotalDifficultyPassed: true,
 		MergeNetsplitBlock:            big.NewInt(1735371),
 		ShanghaiTime:                  newUint64(1677557088),
+		CancunTime:                    newUint64(1706655072),
 		Ethash:                        new(EthashConfig),
 	}
 	// GoerliChainConfig contains the chain parameters to run a node on the Görli test network.