voxtype: restart service when configuration changes

Add the rendered config path to X-Restart-Triggers so the service restarts
whenever the configuration changes.

modules/services/voxtype.nix

@@ -129,6 +129,9 @@ in
       Unit = {
         Description = "Voxtype speech-to-text daemon";
         PartOf = [ "default.target" ];
+        X-Restart-Triggers = mkIf (cfg.settings != { }) [
+          "${config.xdg.configFile."voxtype/config.toml".source}"
+        ];
       }
       // optionalAttrs (cfg.loadModels != [ ]) {
         Wants = [ "voxtype-model-loader.service" ];

tests/modules/services/voxtype/basic-configuration.nix

@@ -29,6 +29,7 @@
     assertFileRegex "$serviceFile" 'Environment=PATH=.*/bin'
     assertFileRegex "$serviceFile" 'Environment=WAYLAND_DISPLAY=wayland-1'
     assertFileRegex "$serviceFile" 'Environment=VOXTYPE_TEST_ENV=1'
+    assertFileRegex "$serviceFile" 'X-Restart-Triggers=/nix/store/.*-voxtype-config.toml'
 
     assertFileContent "$configFile" ${./expected-config.toml}
   '';