lib: use full URL to GitHub issues in comments

Don't assume the reader of the code will know where to find the issue
tracker. Provide the full URL. This is especially important if the
issue tracker should move again.

PR-URL: https://github.com/nodejs/node/pull/34686


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ricky Zhou <0x19951125@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Mary Marchini <oss@mmarchini.me>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>