refactor(youtube-player): remove standalone flags

Removes the explicit `standalone` flag from the YouTube components.

Author: crisbeto

src/youtube-player/README.md

@@ -20,7 +20,6 @@ import {Component} from '@angular/core';
 import {YouTubePlayer} from '@angular/youtube-player';
 
 @Component({
-  standalone: true,
   imports: [YouTubePlayer],
   template: '<youtube-player videoId="mVjYG9TSN88"/>',
   selector: 'youtube-player-example',

src/youtube-player/youtube-player-placeholder.ts

@@ -28,7 +28,6 @@ export type PlaceholderImageQuality = 'high' | 'standard' | 'low';
       </svg>
     </button>
   `,
-  standalone: true,
   styleUrl: 'youtube-player-placeholder.css',
   host: {
     'class': 'youtube-player-placeholder',

src/youtube-player/youtube-player.ts

@@ -111,7 +111,6 @@ enum PlayerState {
   selector: 'youtube-player',
   changeDetection: ChangeDetectionStrategy.OnPush,
   encapsulation: ViewEncapsulation.None,
-  standalone: true,
   imports: [YouTubePlayerPlaceholder],
   template: `
     @if (_shouldShowPlaceholder()) {