linux: Fix enter key triggering newline instead of commiting input (#39599)

Closes #31337 #35537

Release Notes:

- Fixed an issue on Linux X11 where pressing Enter added a new line
instead of confirming English input.

crates/gpui/src/platform/linux/x11/client.rs

@@ -1315,17 +1315,9 @@ impl X11Client {
             return None;
         };
         let mut state = self.0.borrow_mut();
-        let keystroke = state.pre_key_char_down.take();
         state.composing = false;
         drop(state);
-        if let Some(mut keystroke) = keystroke {
-            keystroke.key_char = Some(text);
-            window.handle_input(PlatformInput::KeyDown(crate::KeyDownEvent {
-                keystroke,
-                is_held: false,
-            }));
-        }
-
+        window.handle_ime_commit(text);
         Some(())
     }