refactor: Remove unnecessary E2E_TEST_TOKEN from docker-compose

E2E_TEST_TOKEN_DEV is sufficient as the teardown logic uses fallback:
- First tries E2E_TEST_TOKEN
- Falls back to E2E_TEST_TOKEN_DEV when env is 'dev'

This change reduces to 3 essential fixes only.

Author: talissoncosta

frontend/docker-compose-e2e-tests.yml

@@ -44,7 +44,6 @@ services:
       context: ../
       dockerfile: frontend/Dockerfile.e2e
     environment:
-      E2E_TEST_TOKEN: some-token
       E2E_TEST_TOKEN_DEV: some-token
       DISABLE_ANALYTICS_FEATURES: 'true'
       FLAGSMITH_API: flagsmith-api:8000/api/v1/