doc: update output of example in AbortController
Actual output of example in AbortController is mismatched. Plus, make reason
parameter as optional in JSDoc.
Refs: https://github.com/nodejs/node/blob/main/doc/api/globals.md#abortcontrollerabortreason Refs: https://github.com/nodejs/node/blob/main/doc/api/globals.md#static-method-abortsignalabortreason