WIP: ✨ Fix CPU consumption

[PavitraS]

Summary

Encountering performance challenges with KCP when dealing with just 100 workspaces. The issues are attributed to

1. protomodels,
2. CR CEL validation, and
3. quota controller.

In an effort to provide a solution, this commit disables the following functionalities:

1. Disabling openapi.ToProtoModels.
2. Disabling CR validation expression feature.
3. Disabling the quota controller.

Related issue(s)

Fixes #3063

Release Notes

TODO: before merge

NONE

[kcp-ci-bot]

Hi @PavitraS. Thanks for your PR.

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[palnabarun]

/ok-to-test

@PavitraS can you also attach the heap profile here along with a screengrab of the hot paths?

[embik]

This PR is targeting release-0.21. Can we please propose merging it into main first and then see if we want to back port it?

[kcp-ci-bot]

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[PavitraS]

/ok-to-test

[sttts]

What are the consequences?

No way to fix the root causes?

[kcp-ci-bot]

Issues go stale after 90d of inactivity.
After a furter 30 days, they will turn rotten.
Mark the issue as fresh with /remove-lifecycle stale.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[sttts]

/remove-lifecycle stale

Keeping this open as it is a good reminder of the work to be done.