OS.shell_open(weblink) does not work on iOS

### Tested versions

3.5.3.stable

### System information

iOS safari

### Issue description

When cliking on a button that has a script in pressed that does:
OS.shell_open(link) ,
it does not work.

More exacly:

func _on_Label_gui_input(event):
if event is InputEventMouseButton and event.pressed:
OS.shell_open(link)

it simply does not do anything.

I tested on iOS safari incognito.

Worked on OSX and Android ok.

Indeed need more testing, including the non incognito mode, and to check if the InputEventMouseButton is even being triggered, will create and post a link with a page that does that.

(And yes, label mouse filter was changed to pass)

### Steps to reproduce

OS.shell_open(link)
weblink on iOS HTML5 export

### Minimal reproduction project (MRP)

will provide a hosted link.

Start with the OS.shell_open(link) call in an iOS Safari HTML5 export and verify whether the input event fires. Compare the behavior with the working macOS and Android cases, then provide the promised hosted minimal reproduction so the failure and expected result can be verified.

Written by the indexing model from the issue text.