DetailedList refresh view can't be activated on macOS 14 (Sonoma)

[freakboy3742]

Describe the bug

When using macOS Sonoma, the DetailedList "pull to refresh" behavior can't be activated.

Steps to reproduce

1. Run the DetailedList example app
2. Try to pull down to refresh the data.

The scroll view won't "bounce" allowing the view to be refreshed.

Expected behavior

It should be possible to invoke refresh.

Screenshots

No response

Environment

• Operating System: macOS Sonoma
• Python version: All? (tested on 3.10)
• Software versions:
  • Toga: 0.4.2

Logs

No response

Additional context

The underlying problem appears to be that scroll elasticity has been disabled in Sonoma. On my test machine, there's no "bounce" on any scroll container if you try to scroll past the limits of the window. Toga-demo is enough to demonstrate this - on Ventura, there's a bounce; on my clean Sonoma install, there isn't.

This came up in testing of #2404 - there's a FIXME in cocoa/widgets/internals/refresh.py:103 that disables code coverage on the branch that would be triggered by a working pull-to-scroll implementation.

However, it appears that pull-to-scroll hasn't been universally disabled - I've checked with someone else who has a Sonoma install, and they do have elasticity in their scroll views.