Update architecture docs to reflect current state of HAS

[johnmcollier]

Updates the Konflux architecture docs to accurately represent the current state of HAS within Konflux: a deployment that runs Kubernetes webhooks for Applications and Component resources

[johnmcollier]

@elsony Good suggestion. I checked through the remaining docs for both HAS, HAS/ and application-service and didn't find anything that was broken by the doc removal.

I do see some outdated references to HAS, so I updated those with one exception: I did not update the architecture diagram and the explanation of it, which I left alone, as it's outside of the scope of these changes, as a number of other changes would need to be made to it as well.

[elsony]

/lgtm