fix(macOS): fix SystemTrayEvent not emitted after calling set_menu

[pewsheen]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes
• No

Checklist

• This PR will resolve [bug] Buggy behaviors of SystemTrayEvent on macOS (fail to set tray menu & fail to get callback) tauri#7364 [bug] On MacOS when a new system_tray_menu is set the on_system_tray_event handler is no longer called tauri#5842
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary
• It can be built on all targets and pass CI/CD.

Other information

We didn't set the tray menu direct to ns_status_bar. Instead, we set it to tray_target.menu and let the tray_target attach it when we click the tray icon.

tao/src/platform_impl/macos/system_tray.rs

Lines 91 to 98 in 731e397

	// attach menu only if provided
	if let Some(menu) = self.system_tray.tray_menu.clone() {
	// We set the tray menu to tray_target instead of status bar
	// Because setting directly to status bar will overwrite the event callback of the button
	// See `make_tray_class` for more information.
	(*tray_target).set_ivar("menu", menu.menu);
	let () = msg_send![menu.menu, setDelegate: tray_target];
	}

However, when calling the set_menu, it sets the new menu to ns_status_bar, not tray_target. Therefore the customized click handler is not triggered

tao/src/platform_impl/macos/system_tray.rs

Lines 146 to 150 in 731e397

	pub fn set_menu(&mut self, tray_menu: &Menu) {
	unsafe {
	self.ns_status_bar.setMenu_(tray_menu.menu);
	}
	}

[amrbashir]

cherry picked in to v0.16 branch in 019d9e9e