Preference "Always show 3mf exporter dialog" doesn't update when you disable the dialog from its own window

Describe the bug When you export as 3mf a dialog is shown. It has a checkbox at the bottom. If you uncheck it, the dialog is no longer shown. There is another checkbox in preferences which does the same thing, however these two check boxes are not synced.

To Reproduce Steps to reproduce the behavior:

1. Make a cube or something.
2. File -> export -> 3mf
3. Uncheck "Always show this dialog" at the bottom.
4. Complete the export.
5. Edit -> Preferences -> Dialogs
6. "Always show 3mf export dialog" will be ticked.
7. File -> Export -> 3mf (the dialog is not shown)
8. Edit -> Preferences -> Dialogs
9. Untick the checkbox
10. Tick the checkbox
11. File -> Export -> 3mf
12. Now the dialog is shown

Expected behavior The checkbox in preferences should reflect the current state of the setting, regardless of where the change was made.

IOW, at step 6 above, the checkbox should NOT be checked.

Code reproducing the issue N/A

Screenshots

Environment and Version info (please complete the following information):

• Xubuntu 24.10, Openscad Nightly (snap appimage) 2025.01.20.ai22731 (git 0272f796a)