Etags invalidation on the Geo secondary

Summary

I've been running some pipeline tests on my Geo machines, and I'm seeing the <group>/<project>/pipelines page on the secondary does not represent the latest state of the pipelines.

Steps to reproduce

1. Set up Geo
2. (on primary) Trigger a pipeline
3. (on secondary) Check the pipelines page of the project, the triggered pipeline will be there
4. (on primary) Trigger another pipeline
5. (on secondary) Check the pipelines page of the project again

What is the current bug behavior?

Only the pipeline shown the first time is there, not the pipeline after triggering a second one.

Although for some reason, after x amount of time, it seems to recover and a 200 is sent (maybe the Etags mechanism forces a refresh every once in a while)

What is the expected correct behavior?

Both pipelines should be there.

Relevant logs and/or screenshots

Possible fixes

Etag invalidation should happen on the secondary so the user no longer will get a 304 on <group>/<project>/pipelines.json request.