Update subtlecrypto examples after updates to content

[bsmth]

What information was incorrect, unhelpful, or incomplete?

object literal shorthand used in content but not yet here

What did you expect to see?

See https://github.com/mdn/content/pull/39657/files#diff-12e29f1ce3a1b155e75b708ef543437aaabe920f24e5cb4697e2187b11112b09

Do you have any supporting links, references, or citations?

No response

Do you have anything more you want to share?

No response