Link to Libera, Matrix instead of Freenode

The project has moved away from Freenode as an IRC network[1], and there
is now a quite large channel on Libera.  As such, we should point users
towards that instead.

This also changes all examples to refer to libera instead of freenode
as, with the recent deletion of all freenode channels, it is perhaps
where most communities are to be found nowadays.

Finally, also link to the official Matrix room[2] as an alternative to
IRC.

Related: https://github.com/NixOS/nixpkgs/pull/129384

[1]: https://discourse.nixos.org/t/join-us-on-matrix-at-nix-nixos-org-migrating-from-freenode
[2]: https://github.com/NixOS/rfcs/pull/94

.github/STALE-BOT.md

@@ -3,7 +3,7 @@
 - Thanks for your contribution!
 - To remove the stale label, just leave a new comment.
 - _How to find the right people to ping?_ → [`git blame`](https://git-scm.com/docs/git-blame) to the rescue! (or GitHub's history and blame buttons.)
-- You can always ask for help on [our Discourse Forum](https://discourse.nixos.org/) or on the [#nixos IRC channel](https://webchat.freenode.net/#nixos).
+- You can always ask for help on [our Discourse Forum](https://discourse.nixos.org/), [our Matrix room](https://matrix.to/#/#nix:nixos.org), or on the [#nixos IRC channel](https://web.libera.chat/#nixos).
 
 ## Suggestions for PRs
 

doc/builders/packages/weechat.section.md

@@ -41,7 +41,7 @@ weechat.override {
   configure = { availablePlugins, ... }: {
     init = ''
       /set foo bar
-      /server add freenode chat.freenode.org
+      /server add libera irc.libera.chat
     '';
   };
 }

nixos/doc/manual/preface.xml

@@ -18,12 +18,13 @@
  <para>
   If you encounter problems, please report them on the
   <literal
-   xlink:href="https://discourse.nixos.org">Discourse</literal> or
-  on the <link
+   xlink:href="https://discourse.nixos.org">Discourse</literal>,
+  the <link
+   xlink:href="https://matrix.to/#nix:nixos.org">Matrix room</link>,
+  or on the <link
    xlink:href="irc://irc.libera.chat/#nixos">
-  <literal>#nixos</literal> channel on Libera.Chat</link>, or
-  consider
-  <link
+  <literal>#nixos</literal> channel on Libera.Chat</link>.
+  Alternatively, consider <link
    xlink:href="#chap-contributing">
    contributing to this manual</link>. Bugs should be
   reported in

nixos/modules/services/networking/matterbridge.nix

@@ -38,8 +38,8 @@ in
           # Use services.matterbridge.configPath instead.
 
           [irc]
-              [irc.freenode]
-              Server="irc.freenode.net:6667"
+              [irc.libera]
+              Server="irc.libera.chat:6667"
               Nick="matterbot"
 
           [mattermost]
@@ -55,7 +55,7 @@ in
           name="gateway1"
           enable=true
               [[gateway.inout]]
-              account="irc.freenode"
+              account="irc.libera"
               channel="#testing"
 
               [[gateway.inout]]

nixos/modules/services/networking/znc/default.nix

@@ -133,8 +133,8 @@ in
               Nick = "paul";
               AltNick = "paul1";
               LoadModule = [ "chansaver" "controlpanel" ];
-              Network.freenode = {
-                Server = "chat.freenode.net +6697";
+              Network.libera = {
+                Server = "irc.libera.chat +6697";
                 LoadModule = [ "simple_away" ];
                 Chan = {
                   "#nixos" = { Detached = false; };

nixos/modules/services/networking/znc/options.nix

@@ -11,7 +11,7 @@ let
 
       server = mkOption {
         type = types.str;
-        example = "chat.freenode.net";
+        example = "irc.libera.chat";
         description = ''
           IRC server address.
         '';
@@ -150,8 +150,8 @@ in
           '';
           example = literalExample ''
             {
-              "freenode" = {
-                server = "chat.freenode.net";
+              "libera" = {
+                server = "irc.libera.chat";
                 port = 6697;
                 useSSL = true;
                 modules = [ "simple_away" ];