fix(yargs): remove onFinishCommand

This function was removed by yargs/yargs#1823 (according to yargs/yargs#1947).

types/yargs/index.d.ts

@@ -472,12 +472,6 @@ declare namespace yargs {
         number<K extends keyof T>(key: K | readonly K[]): Argv<Omit<T, K> & { [key in K]: ToNumber<T[key]> }>;
         number<K extends string>(key: K | readonly K[]): Argv<T & { [key in K]: number | undefined }>;
 
-        /**
-         * Method to execute when a command finishes successfully.
-         * @param func Is called with the successful result of the command that finished.
-         */
-        onFinishCommand(func: (result: any) => void): Argv<T>;
-
         /**
          * This method can be used to make yargs aware of options that could exist.
          * You can also pass an opt object which can hold further customization, like `.alias()`, `.demandOption()` etc. for that option.