fix instantiate TTSManager immediately

src/modules/tts.ts

@@ -65,10 +65,9 @@ export class TTSManager {
 	/*
 		singleton logic
 	*/
-	static #instance: TTSManager | null = null;
+	static #instance: TTSManager = new TTSManager();
 
 	public static get get(): TTSManager {
-		if (!TTSManager.#instance) TTSManager.#instance = new TTSManager();
 		return TTSManager.#instance;
 	}
 }