feat(developer): add hint when `store(&targets)` has overlapping sets selected

Not super important, but if you're making changes in this area anyway...
Would you consider adding a warning for cases that are not wrong, but perhaps confusing? I'm thinking primarily of:
- any windows macos linux web ... (where the user has checked all the boxes)

but maybe "any" plus another box would also fall in that category.

_Originally posted by @DavidLRowe in https://github.com/keymanapp/keyman/issues/11918#issuecomment-2211076830_