refactor(module:select): remove internal comment from select-arrow (#9074)

Author: Laffery

components/select/select-arrow.component.ts

@@ -10,9 +10,6 @@ import { NzSafeAny } from 'ng-zorro-antd/core/types';
 import { numberAttributeWithInfinityFallback } from 'ng-zorro-antd/core/util';
 import { NzIconModule } from 'ng-zorro-antd/icon';
 
-/**
- * @internal
- */
 @Component({
   selector: 'nz-select-arrow',
   encapsulation: ViewEncapsulation.None,