editor: Show hidden mouse cursor on window activation (#31475)

Closes #31349

Release Notes:

- Fixed issue where hidden mouse cursor would stay hidden even after
switching windows.

crates/editor/src/editor.rs

@@ -1921,6 +1921,9 @@ impl Editor {
                             blink_manager.disable(cx);
                         }
                     });
+                    if active {
+                        editor.show_mouse_cursor();
+                    }
                 }),
             ],
             tasks_update_task: None,
@@ -2159,6 +2162,10 @@ impl Editor {
         key_context
     }
 
+    fn show_mouse_cursor(&mut self) {
+        self.mouse_cursor_hidden = false;
+    }
+
     pub fn hide_mouse_cursor(&mut self, origin: &HideMouseCursorOrigin) {
         self.mouse_cursor_hidden = match origin {
             HideMouseCursorOrigin::TypingAction => {