refactor(core): decouple gin from pkg/util and reduce code duplication

backend/core/extpoints/task.go

@@ -107,21 +107,9 @@ func (t *TaskRegistry) Register(pattern string, handler any, opts ...TaskOption)
 
 // Unregister removes a registered task definition by its pattern.
 func (t *TaskRegistry) Unregister(pattern string) bool {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	if _, exists := t.lookup[pattern]; !exists {
-		return false
-	}
-
-	delete(t.lookup, pattern)
-	for i, item := range t.tasks {
-		if item.Pattern == pattern {
-			t.tasks = append(t.tasks[:i], t.tasks[i+1:]...)
-			break
-		}
-	}
-	return true
+	return unregisterEntry(&t.mu, t.lookup, &t.tasks, pattern, func(item TaskDefinition) bool {
+		return item.Pattern == pattern
+	})
 }
 
 // Tasks returns a copy of all registered TaskDefinitions.