Remove role=document from terminal element

Part of microsoft/vscode#98918

src/browser/Terminal.ts

@@ -408,7 +408,6 @@ export class Terminal extends CoreTerminal implements ITerminal {
     this.element.classList.add('terminal');
     this.element.classList.add('xterm');
     this.element.setAttribute('tabindex', '0');
-    this.element.setAttribute('role', 'document');
     parent.appendChild(this.element);
 
     // Performance: Use a document fragment to build the terminal