bug(iOS): Crash while return from keyboard help page on simulator (random)

### Describe the bug

I got a crash while return from Installed languages menu using Back button in iPad Air (5th generation - iOS 16.0) Simulator

### Reproduce the bug

Here, What I did is:
1. Installed Keyman 17.0.19-alpha build in iPad Air 5th generation - iOS 16.0 Simulator.
2. Opened the Keyman In-app.
3. Installed 2 more languages (Khmer Angkor and Tamil99 Basic).
4. Verified that the two keyboards were working fine.
5. Closed the app.
6. Relaunched it.
7. Typed words in the text area.
8. Opened the Settings / Installed languages menu.
9. Randomly clicked and opened the Help page of the available keyboards.
10. Clicked the Back button continuously to return to the Text area view and got the below crash,

Note: Tried to reproduce it in the Simulator and it seems to be a random one.

### Expected behavior

It should not crash after clicking the Back button.

### Related issues

_No response_

### Keyman apps

- [ ] Keyman for Android
- [X] Keyman for iPhone and iPad
- [ ] Keyman for Linux
- [ ] Keyman for macOS
- [ ] Keyman for Windows
- [ ] Keyman Developer
- [ ] KeymanWeb
- [ ] Other - give details at bottom of form

### Keyman version

17.0.19-alpha

### Operating system

iOS 16.0

### Device

iPad Air 5th generation

### Target application

Keyman In-App

### Browser

_No response_

### Keyboard name

khmer_angkor, tamil99basic

### Keyboard version

1.3,2.0.3

### Language name

Khmer, Tamil

### Additional context

_No response_