cmd/utils: make --authrpc.jwtsecret a DirectoryFlag (#25849)

Signed-off-by: Delweng <delweng@gmail.com>

cmd/utils/flags.go

@@ -631,7 +631,7 @@ var (
 		Value:    strings.Join(node.DefaultConfig.AuthVirtualHosts, ","),
 		Category: flags.APICategory,
 	}
-	JWTSecretFlag = &cli.StringFlag{
+	JWTSecretFlag = &flags.DirectoryFlag{
 		Name:     "authrpc.jwtsecret",
 		Usage:    "Path to a JWT secret to use for authenticated RPC endpoints",
 		Category: flags.APICategory,