Update IRC server to libera

Author: laanwj

_posts/en/posts/2021-09-13-release-22.0.md

@@ -23,8 +23,8 @@ If have any questions, please stop by the #bitcoin IRC chatroom
 ([IRC][irc], [web][web irc]) and we’ll do our best to help you.
 
 [release notes]: /en/releases/22.0/
-[IRC]: irc://irc.freenode.net/bitcoin
-[web irc]: https://webchat.freenode.net/#bitcoin
+[IRC]: irc://irc.libera.chat/bitcoin
+[web irc]: https://web.libera.chat/#bitcoin
 [download page]: /en/download
 
 {% include references.md %}