remove writeUtf8 from core

src/Terminal.ts

@@ -1191,13 +1191,6 @@ export class Terminal extends Disposable implements ITerminal, IDisposable, IInp
     }
   }
 
-  /**
-   * @deprecated use write instead
-   */
-  public writeUtf8(data: Uint8Array, callback?: () => void): void {
-    this.write(data, callback);
-  }
-
   /**
    * Writes text to the terminal, followed by a break line character (\n).
    * @param data The text to write to the terminal.