Fix for crash when dismissing UIViewControllers when building with Xcode 26

[StuSharpe]

Addresses #313

This change re-instates the original thread-hop before nilling out dismiss closure that was present in 2.5.0, for the non-UIAlertController case.

See 2.5.0...2.5.1

This fixes the issue, but I don't really have any clarity on why. Some quirk with the Xcode 26 toolset.

[StuSharpe]

@acosmicflamingo - keen for your opinion on this

[StuSharpe]

Tested on:

• Xcode 16.4
• Xcode 26.0.1
• iOS 18.5 Simulator & iOS 18.6 (iPhone 11 Pro)
• iOS 26.0 (Simulator & Phone 15 Pro)

[acosmicflamingo]

Interesting...I wonder if this has an impact on TCA apps that display alerts via state navigation. I'm not by my keyboard so I can't verify. What a find!

[StuSharpe]

Have tried in my own TCA app, and the alerts and confirmation dialogs still seem to work as expected. The codepath for this shouldn't affect the 2.5.1 behavior.

Would be great verify on another TCA code base though.

[StuSharpe]

Hmm, it's a bit hard to fully validate in TCA without this PR included as things keep getting dismissed: #310

@acosmicflamingo Maybe we should wait until your other PR is merged in.

[stephencelis]

Oops didn't mean to close! @StuSharpe now that #310 is merged and you verify everything on your end?

[StuSharpe]

Thanks @stephencelis. Yes, I can confirm that all looks good now. Happy for this to be merged.

Tested:

• Example project, Xcode 26, Simulator & Device (iOS 26)
• My TCA project XCode 26, Simulator and Device (iOS 26)
• Example project, Xcode 16.4 Simulator (iOS 18.5)
• My TCA project, Xcode 16.5, Device iOS 18.6