cmd, eth, les: replace Shanghai override flag with Cancun (#27171)

cmd/geth/config.go

@@ -158,9 +158,9 @@ func makeConfigNode(ctx *cli.Context) (*node.Node, gethConfig) {
 // makeFullNode loads geth configuration and creates the Ethereum backend.
 func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 	stack, cfg := makeConfigNode(ctx)
-	if ctx.IsSet(utils.OverrideShanghai.Name) {
-		v := ctx.Uint64(utils.OverrideShanghai.Name)
-		cfg.Eth.OverrideShanghai = &v
+	if ctx.IsSet(utils.OverrideCancun.Name) {
+		v := ctx.Uint64(utils.OverrideCancun.Name)
+		cfg.Eth.OverrideCancun = &v
 	}
 	backend, eth := utils.RegisterEthService(stack, &cfg.Eth)
 

cmd/geth/main.go

@@ -64,7 +64,7 @@ var (
 		utils.NoUSBFlag,
 		utils.USBFlag,
 		utils.SmartCardDaemonPathFlag,
-		utils.OverrideShanghai,
+		utils.OverrideCancun,
 		utils.EnablePersonal,
 		utils.EthashCacheDirFlag,
 		utils.EthashCachesInMemoryFlag,