[processor/k8sattributes] Fix k8s.node.uid extraction when node.name is disabled

[Rishab-And-Abhisekh-joint]

Description:
Fixes #43865. Previously, k8s.node.uid was only added if k8s.node.name was also requested in the configuration. This PR decouples the logic so UID can be fetched independently.

Testing:
Added a unit test case validating k8s.node.uid is present even when k8s.node.name is omitted.

Credit:
Logic based on investigation by @LeonLow97.

[linux-foundation-easycla]

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• ✅ login: Rishab-And-Abhisekh-joint / name: Rishab_Acharjee (a4960d9, 2fe8237)

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[ChrsMark]

Please remove the unnecessary additions. Otherwise it looks good.

[ChrsMark]

Sth looks weird.

[Rishab-And-Abhisekh-joint]

Thanks for the catch @ChrsMark. I realized the issue was that I was initializing the client (c) outside the loop, which caused shared state between the test cases.

I’ve moved the client initialization inside t.Run so each test case starts with a clean state. I also removed the commented-out code and ran make fmt. Ready for another look!

[ChrsMark]

I don't see why we need to change the existing tests for this patch.

The current state of the PR is incomplete since the actual fix has been reverted since I approved the PR.

Please ensure that the PR is actually ready for review with only the required/necessary changes implemented.