Call xterm internal _syncTextArea function

As workaround to fix invalid textarea position when the user resize the browser window

frontend/public/components/terminal.jsx

@@ -116,6 +116,10 @@ class Terminal_ extends React.Component {
       this.fitAddon.fit();
       // update the pty
       this.props.onResize(terminal.rows, terminal.cols);
+      // The internal xterm textarea was not repositioned when the window was resized.
+      // This workaround triggers an position update.
+      // See https://github.com/xtermjs/xterm.js/issues/3390
+      terminal._core?._syncTextArea?.();
     });
   }