[bitcoin/bitcoin] [doc] Add new regtest ports in man following #10825 ports reattributions (#14013)

Following #10825, regtest ports for p2p connections and JSON-RPC connections have been remapped from 18333 and 18332 to 18444 and 18443. This change is not documented in the wiki or nowhere else and it’s puzzling to guess why your regtest JSON-rpc connections all failed even if you’re following the docs.
You can view, comment on, or merge this pull request online at:

https://github.com/bitcoin/bitcoin/pull/14013

— Commit Summary —

* Add new regtest ports in man following #10825 ports reattributions

— File Changes —

M doc/man/bitcoind.1 (6)

— Patch Links —

https://github.com/bitcoin/bitcoin/pull/14013.patch
https://github.com/bitcoin/bitcoin/pull/14013.diff