Enabling/disabling resource packs is not saved after leaving the editing world menu.

Steps to reproduce:

1. Open a world’s editing menu.

2. Activate or deactivate a resource pack without making any other adjustments.

3. Exit the menu.

4. Go back to the edit world menu again, and check the activated resource packs.

Expected result:

The adjustments you made should be saved.

Actual result:

They were not.

Note:

Currently, a workaround is to enable/disable the "shared pack" option and click "Save Changes" before leaving.