Stop mirroring `incrementals` from ACP

[jglick]

Service(s)

Artifact-caching-proxy

Summary

Splitting this out of #4990 for clarity.

• Revert Do not mirror the incrementals repo jenkins-infra#4669 as it did not help.
• Must be paired with Pass -P-consume-incrementals unless a PR specifically includes marker file consume-incrementals pipeline-library#991 to avoid a performance regression (Artifact Caching Proxy (ACP) does not cache artifacts from Maven Central #3969 (comment)) by not asking about this repo except in rare cases.

[rantoniuk]

That change needs to be reverted and we need to switch from Dependabot to Renovate as soon as we can reasonably do so. More details about the Dependabot issue are described in

this issue. So what is exactly the issue with Dependabot and why Renovate would be a better choice? cc @MarkEWaite

I would guess it's not an issue with Dependabot itself, but a configuration issue that allows Dependabot to see incrementals repository/artefacts that are not consumable.

[jglick]

I would guess it's not an issue with Dependabot itself

It was acknowledged as a regression in DB. See linked issues for discussion. This issue is about preparing for jenkins-infra/pipeline-library#991 as a general defense regardless of what tool (or person!) proposes an update.