shiny/driver/gldriver: stop activating regardless of the current app

Documentation for NSApplicationActivateIgnoringOtherApps warns:

> Important: You should rarely pass this flag because stealing
> key focus produces a poor user experience.

The flag is also deprecated and no longer has effect in macOS 14.
Stop setting it.

Change-Id: I8b8794332b54445866e038d9537a4b0eb4e75149
Cq-Include-Trybots: luci.golang.try:x_exp-gotip-darwin-amd64_14
Reviewed-on: https://go-review.googlesource.com/c/exp/+/532581
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

shiny/driver/gldriver/cocoa.m

@@ -233,7 +233,7 @@ @interface AppDelegate : NSObject<NSApplicationDelegate>
 @implementation AppDelegate
 - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
 	driverStarted();
-	[[NSRunningApplication currentApplication] activateWithOptions:(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)];
+	[[NSRunningApplication currentApplication] activateWithOptions:NSApplicationActivateAllWindows];
 }
 
 - (void)applicationWillTerminate:(NSNotification *)aNotification {