Ignore key-release keyboard events (#6139)

Since crossterm 0.26.x, we receive press/release keyboard events on
Windows always. We can ignore the release events though to emulate
the behavior of keyboard input on Windows on crossterm 0.25.x.

helix-term/src/application.rs

@@ -638,6 +638,11 @@ pub async fn handle_terminal_events(
                 self.compositor
                     .handle_event(&Event::Resize(width, height), &mut cx)
             }
+            // Ignore keyboard release events.
+            CrosstermEvent::Key(crossterm::event::KeyEvent {
+                kind: crossterm::event::KeyEventKind::Release,
+                ..
+            }) => false,
             event => self.compositor.handle_event(&event.into(), &mut cx),
         };