overlay: pin matrix-appservice-irc to nodejs-slim 22

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jaysa68

flake.nix

@@ -366,6 +366,10 @@
           nativeBuildInputs = (old.nativeBuildInputs or [ ]) ++ [ final.rpcsvc-proto ];
           configureFlags = (old.configureFlags or [ ]) ++ [ "--enable-rpc" ];
         });
+
+        matrix-appservice-irc = prev.matrix-appservice-irc.override {
+          nodejs-slim = final.nodejs-slim_22;
+        };
       };
 
       agenix-rekey = agenix-rekey.configure {