🌱 Kcp use one workload cluster for reconcile

[fabriziopandini]

What this PR does / why we need it:
As of today, KCP creates the workloadCluster internal struct several times during every reconciliation, and this is one of the factors slowing down reconciliation duration in a way that can impact performance at scale.

This PR refactor KCP so only one workloadCluster internal struct is going to be created and re-used all around during the same reconcile

Which issue(s) this PR fixes:
Part of #8814

[fabriziopandini]

/test pull-cluster-api-e2e-full-main

[sbueringer]

Nice, just two nits

[fabriziopandini]

/retest

[fabriziopandini]

/test pull-cluster-api-e2e-full-main

[sbueringer]

/lgtm
code looks good.

Not sure about the unit test failure. Just a guess, maybe a race condition with the cache?

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 2441217d5c3b7a7e9e6705761acae9f2a8aee955

[sbueringer]

/lgtm
/approve

/hold
for squash and if you want to wait for other reviews

P.S. I was using this commit yesterday during scale tests and everything worked well

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 69037646a93380793ae4251266b9f201b8abdc61

[sbueringer]

/lgtm

(keeping hold for squash)

[killianmuldoon]

I haven't tested the performance impact of this, but the changes in the code make complete sense.

/lgtm
/approve

(I think you can unhold whenever you'd like @fabriziopandini)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: killianmuldoon, sbueringer

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• OWNERS [killianmuldoon,sbueringer]

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[fabriziopandini]

/hold cancel

[sbueringer]

I haven't tested the performance impact of this, but the changes in the code make complete sense.

I can't speak about the exact delta, but overall everything worked and the performance got better

[killianmuldoon]

/area provider/control-plane-kubeadm