Flights > Index / Search page not showing all available flights

[FatihKoz]

When restrict aircraft to rank or restrict aircraft to type rating setting is enabled, flights without subfleet assignments are not being displayed on flight index/search page.

Version
7.0.0-dev+231027.67ef30

To Reproduce

1. Go to admin > flights, edit a flight and remove all subfleets
2. Go to admin > settings, enable restrict aircraft to rank (and assign some subfleets to your rank if not done already)
3. Go to frontend > flights and check the result (the flight you removed subfleets from will not be listed)

Expected behavior
Rank / Type Rating limitation should only apply to flights with assigned subfleets. If a flight has no subfleets assigned, this simply should mean that it is open to all (as it was before)