chore: Add pod metrics

[jigisha620]

Fixes #N/A

Description Adding pod metrics -

1. current_unbound_time_seconds
2. bound_duration_seconds
3. unstarted_time_seconds

How was this change tested?

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[k8s-ci-robot]

Hi @jigisha620. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[coveralls]

Pull Request Test Coverage Report for Build 11225530907

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 51 of 51 (100.0%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.1%) to 80.807%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controllers/provisioning/scheduling/nodeclaim.go	2	89.13%
<!--	Total:	2		-->

Totals
Change from base Build 11189038895:	0.1%
Covered Lines:	8488
Relevant Lines:	10504

---

💛 - Coveralls

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jigisha620, jonathan-innis

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/kubernetes-sigs/karpenter/blob/main/OWNERS)~~ [jonathan-innis] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment