Revert "Bump Go version to 1.23.6 (#30242)" (#30359)

This reverts commit acbbd4c58d.

server/channels/app/plugin.go

@@ -237,10 +237,10 @@ func (ch *Channels) initPlugins(c request.CTX, pluginDir, webappPluginDir string
 	// Sync plugin active state when config changes. Also notify plugins.
 	ch.pluginsLock.Lock()
 	ch.RemoveConfigListener(ch.pluginConfigListenerID)
-	ch.pluginConfigListenerID = ch.AddConfigListener(func(oldCfg, newCfg *model.Config) {
+	ch.pluginConfigListenerID = ch.AddConfigListener(func(old, new *model.Config) {
 		// If plugin status remains unchanged, only then run this.
 		// Because (*App).InitPlugins is already run as a config change hook.
-		if *oldCfg.PluginSettings.Enable == *newCfg.PluginSettings.Enable {
+		if *old.PluginSettings.Enable == *new.PluginSettings.Enable {
 			ch.syncPluginsActiveState()
 		}