TypeError: Cannot read properties of null (reading 'environments')

Sentry Issue: [FLAGSMITH-FRONTEND-4N3](https://flagsmith.sentry.io/issues/7478716290/?referrer=github_integration)

```
TypeError: Cannot read properties of null (reading 'environments')
  at store.getEnvironmentIdFromKey (./common/stores/project-store.js:179:34)
  at eMr (./web/components/CompareIdentities.tsx:63:17)
...
(6 additional frame(s) were not displayed)
```