fix: restore original BrowserWindow.show() behavior (#42305)

The new activate API on macOS is pretty bad, we should just keep using
the old API. Similar to #42180. Restores non-panel behavior to pre-panel
support.

Notes: BrowserWindow.show() now correctly restores focus to inactive apps on macOS

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Samuel Attard <[email protected]>

shell/browser/native_window_mac.mm

@@ -457,11 +457,7 @@ void NativeWindowMac::Show() {
 
   // Panels receive key focus when shown but should not activate the app.
   if (!IsPanel()) {
-    if (@available(macOS 14.0, *)) {
-      [[NSApplication sharedApplication] activate];
-    } else {
-      [[NSApplication sharedApplication] activateIgnoringOtherApps:YES];
-    }
+    [[NSApplication sharedApplication] activateIgnoringOtherApps:YES];
   }
   [window_ makeKeyAndOrderFront:nil];
 }