crypto: remove DEFAULT_ENCODING
Citing 76b0bdf7 from 2012, "only use this as a temporary measure."
Getting or setting DEFAULT_ENCODING
has emitted a warning ever since Node.js 10, so it seems appropriate to remove it in Node.js 20 five years later. The last Node.js version that did not emit a warning reached its end-of-life status at the end of 2019.
This commit only removes the public API so that the change can land in time for Node.js 20.
Refs: https://github.com/nodejs/node-v0.x-archive/pull/4179 Refs: https://github.com/nodejs/node/pull/18333