Expected behavior

OR works reliably when deleting an accidentally-created simulation.

To Reproduce

1. With a fresh instance of OpenRocket, File>Open example>TARC payload rocket.
2. Cancel "Rocket configuration" dialog.
3. Click to Flight simulations tab.
4. Click "New simulation", OK its dialog.
5. Click "Delete simulations" (the just-added sim is highlighted already)
6. OK the "are you sure" dialog
7. Click "Motors & Configuration" tab. Note the existing single config for [None;F50-9] - this is as it should be.
8. Click "New Configuration".
9. Select an Aerotech E30-4 from the dialog (probably not important which motor) and OK the motor selection dialog.
10. Note presence of configs for [None;F50-9] and [None;E30-4] - this is as it should be.
11. Click the "Flight simulations" tab.
12. Note two simulations, one for each of the two configs - this is as it should be.
13. Save the file
14. Cancel the "Save design info" dialog, and click Yes for the "are you sure" warning.
15. BEFORE selecting a file name, note that the Flight simulations tab has now lost the motor for Simulation 2
16. Save the file someplace convenient.
17. Choose a filename and save
18. Save "Only summary data"
19. Quit OpenRocket.

Note that items 20 and forward refer to a table resizing issue on macOS that's probably related to the problems with the OR file. But the file has already been saved without a motor, and if it's corrupt, it already is by this point.

20. Re-open OpenRocket by double-clicking on the saved-file.ork icon (File>Open will not repro the macOS table re-sizing behavior from opening the (corrupt?) file).
21. Click on "Flight simulations" tab.
22. Click on "Simulation 2" (or [SHIFT]+click to add "Simulation 2")
23. Click "Run simulations".
24. Click on Motors & Configuration tab.
25. Note that there are no configurations. In actuality, on macOS, the Motors and Configuration window has (as a result of these steps) been sized down so only the column titles show. The configurations are there (one with no motor), visible after making more space in the Motors & Config window. Discovered this after more testing. Not resizing in this way on Win ARM64 and Linux ARM64.