perf: map clear (yomorun#753)

# Description

Use the built-in function(clear) to delete all map elements.

core/context.go

@@ -139,7 +139,5 @@ func (c *Context) reset() {
 	c.Frame = nil
 	c.FrameMetadata = nil
 	c.Logger = nil
-	for k := range c.Keys {
-		delete(c.Keys, k)
-	}
+	clear(c.Keys)
 }

core/router/router.go

@@ -100,11 +100,6 @@ func (r *defaultRouter) Release() {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
-	for key := range r.targets {
-		delete(r.targets, key)
-	}
-
-	for key := range r.data {
-		delete(r.data, key)
-	}
+	clear(r.targets)
+	clear(r.data)
 }

pkg/bridge/ai/service.go

@@ -114,9 +114,7 @@ func (s *Service) Release() {
 	if s.reducer != nil {
 		s.reducer.Close()
 	}
-	// INFO: use clear on go1.21 or later
-	// clear(s.cache)
-	s.cache = map[string]*CacheItem{}
+	clear(s.cache)
 }
 
 func (s *Service) createSource() (yomo.Source, error) {