router: removing envoy.reloadable_features.outlier_detection_support_for_grpc…

[alyssawilk]

Risk Level: Low (deprecated since October)
Testing: n/a
Docs Changes: n/a
Release Notes: n/a
fixes #8845

[alyssawilk]

As an aside to @envoyproxy/maintainers do we think we should have warnings for folks potentially setting runtime guards to false? I feel like we have enough documentation for each guard "this is going away" and "this is temporary", and they're mainly in case anyone has an issue, that I'm inclined to not bother until/if someone complains, but it occurred to me to ask.

[mattklein123]

but it occurred to me to ask.

I think this would be a really nice thing to do, but I don't think it should block the cleanups. Maybe track as an issue?

[alyssawilk]

SG, will do as a follow-up and add these 2 in

[asraa]

Thanks! Would you also be able to update the docs about outlier detection? There's a reference about the runtime feature here: https://github.com/envoyproxy/envoy/blob/master/docs/root/intro/arch_overview/upstream/outlier.rst#grpc

[alyssawilk]

oh nice catch - I usually discourage documenting the transient guards. Fixed!

[asraa]

Thank you!