WIP: node: cm: use maps.Clone instead of reinvent it

[ffromani]

/kind cleanup

What this PR does / why we need it:

As emerged during the review of #128657 (comment) , golang stdlib now features helpers in maps and slices package we can use instead of reinventing in our codebase

Which issue(s) this PR fixes:

Fixes N/A

Special notes for your reviewer:

N/A

Does this PR introduce a user-facing change?

NONE

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[ffromani]

WIP because I'd like to lookup for more instances and clean them up

[SergeyKanzhelev]

WIP because I'd like to lookup for more instances and clean them up

sure. Ping when ready.

[haircommander]

personally I'd drop this function entirely as it just uses a stdlib function anyway

[ffromani]

I thought about it. I'd argue that if we bothered to create a type around essentially a map, we should not break the abstraction, and if so we need the trivial Clone method.

Other (more far-fetching?) options:

• dissolve ContainerMap and make use an actual map + helper functions
• make ContainerMap more opaque, fully wrap it into a struct, to open the option in the future to add locks (spoiler: node: cm: don't share containerMap instances between managers #128657 was caused largely because I incorrectly remembered ContainerMap is more than such a thin wrapper. I confused it with pod_devices)

I'm open to conversation here.

[ffromani]

/retest

[k8s-ci-robot]

@ffromani: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-kubernetes-e2e-gce	12fc5d2	link	true	/test pull-kubernetes-e2e-gce

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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