Update deploy-docs.yaml for use with Flux image automation

[ajhall]

The publishing process for the doc site is changing, so the yesdk image needs to update to go along with it.

This removes the cross-repo checkout, Fastly flush, etc, and simplifies it down to just a Docker image tag/push.

[DennisDyallo]

Hi @ajhall ! I see this is a draft. Is it good to merge or are you still working on it?

[Copilot]

Pull request overview

Updates the documentation deployment workflow to align with the new Flux image automation flow by removing cross-repo GitOps updates and cache purging, and instead creating additional image tags in Artifact Registry.

Changes:

• Replaces GitOps repo checkout/commit flow with gcloud artifacts docker tags add tagging.
• Removes the deploy verification job (commit-status wait + Fastly purge).
• Simplifies inputs to an environment selector (dev/prod) plus image-tag.

[ajhall]

Hi @ajhall ! I see this is a draft. Is it good to merge or are you still working on it?

Almost ready! Right now there are two deployments of the doc site running in parallel with each other, and this PR will make it stop updating the US1 deployment (currently live) and start working with the US2 deployment. I don't think I need any other code changes, it's more of a timing issue.

If you don't think you'll be pushing out any doc changes in the next few weeks, we can merge this now, it'll start updating the US2 site, and any changes you push out in the meantime will go live when the docs team is ready to flip everything to the new location.

If you want to be able to keep pushing out docs at any time, though, we can either wait until US2 is live and then merge this PR (that's why I left it as a draft for now), or split it up into multiple PRs: one to update US1/US2 in parallel, and another one later to remove US1. Let me know which you'd prefer.

[DennisDyallo]

@ajhall Ok, well actually, I will want to push new release notes today 😅

[ajhall]

@DennisDyallo No problem! Let's leave this as a draft and I'll activate it after the docs site has flipped over to the new cluster.

[DennisDyallo]

Sounds good @ajhall thanks for the quick response!