Nested permissions not returning 404 for missing parent entities

Sentry Issue: [FLAGSMITH-API-5G4](https://flagsmith.sentry.io/issues/7194925576/?referrer=github_integration)

```
Environment.DoesNotExist: Environment matching query does not exist.
(9 additional frame(s) were not displayed)
...
File "features/versioning/views.py", line 222, in initial
super().initial(request, *args, **kwargs)
File "features/versioning/permissions.py", line 73, in has_permission
environment = Environment.objects.get(id=environment_pk)
```