Use avahi-daemon release candidate

Let's see if this fixes the high CPU load issues.

modules/avahi.nix

@@ -1,8 +1,35 @@
-{ config, lib, ... }:
+{ config, lib, pkgs, ... }:
 
 lib.mkIf config.jalr.gui.enable {
   services.avahi = {
     enable = true;
+    package =
+      let
+        xmltoman = pkgs.xmltoman.overrideAttrs (_: {
+          nativeBuildInputs = [
+            pkgs.installShellFiles
+          ];
+          buildInputs = [
+            (pkgs.perl.withPackages (pl: [
+              pl.XMLParser
+            ]))
+          ];
+        });
+      in
+      pkgs.avahi.overrideAttrs (o: rec {
+        version = "0.9-rc2";
+        src = pkgs.fetchurl {
+          url = "https://github.com/avahi/avahi/archive/refs/tags/v${version}.tar.gz";
+          sha256 = "sha256-9k7+1qlyz5LLLfs1q/aqkXPWK4Q7FYUML0CvdqQjj4o=";
+        };
+        patches = [ ];
+        buildInputs = o.buildInputs ++ [ pkgs.systemdLibs ];
+        nativeBuildInputs = o.nativeBuildInputs ++ [ xmltoman ];
+        installFlags = [
+          "runstatedir=${placeholder "out"}/run"
+          "sysconfdir=${placeholder "out"}/etc"
+        ];
+      });
     nssmdns4 = true;
     extraConfig = ''
       [server]