Add in-place infeasible cached metric

[omerap12]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Adds a Prometheus counter metric (inplace_cache_pods_total) to track pods that were skipped from in-place updates because the infeasible result was already cached. This provides observability into how often the cache prevents redundant in-place update attempts.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Adds a Prometheus counter metric (inplace_cache_pods_total) to track pods that were skipped from in-place updates because the infeasible result was already cached.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

This issue is currently awaiting triage.

If SIG Autoscaling contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: omerap12

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• vertical-pod-autoscaler/OWNERS [omerap12]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[omerap12]

/retest

[omerap12]

/retest

[adrianmoisey]

is inplace_cache_pods_total descriptive enough?
There are only ever pods that could be infeasible, I wonder if it makes sense to make it something like:
inplace_infeasible_skip_pods_total ?

[omerap12]

fixed.