Opt-in to new Apdex calculation methods

As mentioned in error-budget-reports#4 (closed) we should opt-in to using the new apdex calculation methods by the end of FY23Q1.

See gitlab-com/gl-infra/scalability#1451 for how to opt-in.

Any endpoints that are performing poorly enough to affect our Apdex negatively can be marked as low urgency while we fix the performance issues.