chore: remove the access codes feature flag

config/packages/flagception.yaml

@@ -4,7 +4,6 @@
 # flag gets the state the feature had before it existed. Switching one on is an .env change, not
 # a release.
 flagception:
-    features:
-        access_codes:
-            default: false
-            env: FEATURE_ACCESS_CODES
+    # None at the moment. A new one is an entry here, with `default: false` and an `env` variable
+    # declared in .env.
+    features: {}