all: remove the Rinkeby testnet (#27406)

cmd/clef/README.md

@@ -29,7 +29,7 @@ GLOBAL OPTIONS:
    --loglevel value        log level to emit to the screen (default: 4)
    --keystore value        Directory for the keystore (default: "$HOME/.ethereum/keystore")
    --configdir value       Directory for Clef configuration (default: "$HOME/.clef")
-   --chainid value         Chain id to use for signing (1=mainnet, 4=Rinkeby, 5=Goerli) (default: 1)
+   --chainid value         Chain id to use for signing (1=mainnet, 5=Goerli) (default: 1)
    --lightkdf              Reduce key-derivation RAM & CPU usage at some expense of KDF strength
    --nousb                 Disables monitoring for and managing USB hardware wallets
    --pcscdpath value       Path to the smartcard daemon (pcscd) socket file (default: "/run/pcscd/pcscd.comm")

cmd/clef/main.go

@@ -99,7 +99,7 @@ var (
 	chainIdFlag = &cli.Int64Flag{
 		Name:  "chainid",
 		Value: params.MainnetChainConfig.ChainID.Int64(),
-		Usage: "Chain id to use for signing (1=mainnet, 4=Rinkeby, 5=Goerli)",
+		Usage: "Chain id to use for signing (1=mainnet, 5=Goerli)",
 	}
 	rpcPortFlag = &cli.IntFlag{
 		Name:     "http.port",