OpenTelemetry nil dereference

[sengi]

OTel is logging this nil dereference at quite a rate, nearly 1000/s during daily peak traffic in prod:

ERROR -- : OpenTelemetry error: undefined method `env' for nil:NilClass

Disabled OTel in prod until we figure out what's going on here and fix it.

[theseanything]

The root cause is due to logstasher gem not including the "request" object in the payload for "process_action.action_controller" events. The gem strangely re-implements the event handler. A suggested fix is here shadabahmed/logstasher#185. However, development on that gem is somewhat stale.

[theseanything]

This is a fix from ourside: alphagov/govuk_app_config#372

[theseanything]

Fix has been rolled out and tracing re-enabled in prod.