message: Update doc-tests for passphrase prompt change
diff: //! };
  //!
  //! let decryptor = age::Decryptor::Keys(vec![key]);
  -//! let mut reader = decryptor.trial_decrypt(&encrypted[..], || None)?;
  +//! let mut reader = decryptor.trial_decrypt(&encrypted[..], |_| None)?;
  //! let mut decrypted = vec![];
  //! reader.read_to_end(&mut decrypted);
  //!
  //! };
  //!
  //! let decryptor = age::Decryptor::Passphrase(passphrase.to_owned());
  -//! let mut reader = decryptor.trial_decrypt(&encrypted[..], || None)?;
  +//! let mut reader = decryptor.trial_decrypt(&encrypted[..], |_| None)?;
  //! let mut decrypted = vec![];
  //! reader.read_to_end(&mut decrypted);
  //!
  