💚(ci) add Redis requirement for backend tests

Redis was made a required dependency for running project tests. Update CI
environment to include Redis instance as tests now depend on it for proper
execution. Affects all backend test suites.

This dependency was intorduced by the lobby service.

.github/workflows/meet.yml

@@ -110,6 +110,16 @@ jobs:
           - 5432:5432
         # needed because the postgres container does not provide a healthcheck
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
+      redis:
+        image: redis:5
+        ports:
+          - 6379:6379
+        # Set health checks to wait until redis has started
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
 
     env:
       DJANGO_CONFIGURATION: Test
@@ -121,6 +131,7 @@ jobs:
       DB_USER: dinum
       DB_PASSWORD: pass
       DB_PORT: 5432
+      REDIS_URL: redis://localhost:6379/1
       STORAGES_STATICFILES_BACKEND: django.contrib.staticfiles.storage.StaticFilesStorage
       LIVEKIT_API_SECRET: secret
       LIVEKIT_API_KEY: devkey