doc: update crypto examples to not use deprecated api

Updated Cipher and Decipher examples to not use deprecated
`crypto.createCipher` and `crypto.createDecipher` in examples and
instead use `createCipheriv` and `createDecipheriv`.

Fixes: https://github.com/nodejs/node/issues/24046

PR-URL: https://github.com/nodejs/node/pull/24107


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>