fix: Fix using the wrong pods when validating do-not-evict pods

[jonathan-innis]

Fixes aws/karpenter-provider-aws#4310, aws/karpenter-provider-aws#4758

Description

This PR correctly validates that the candidates that we are attempting to deprovision are still eligible to be deprovisioned. It does this by mapping the old candidates onto the new candidates that we pull from state and checking that all of those candidates are still valid for deprovisioning based on PDB criteria, do-not-evict annotations, and scheduling criteria.

This PR also removes the caching mechanism for validationCandidates since we weren't calling IsValid multiple times in code, meaning that storing the candidates like this wasn't necessary for our usage.

#247 had originally intended to fix this issue, but uses the wrong pods for validation within the filterCandidates function. This causes validation to pass for candidate nodes that receive pods with blocking PDBs or do-not-evict pods within the validation window.

How was this change tested?

make presubmit

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

[coveralls]

Pull Request Test Coverage Report for Build 6473509748

• 6 of 7 (85.71%) changed or added relevant lines in 1 file are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.01%) to 81.881%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/controllers/deprovisioning/validation.go	6	7	85.71%

Files with Coverage Reduction	New Missed Lines	%
pkg/controllers/deprovisioning/validation.go	1	71.05%
pkg/test/cachesyncingclient.go	2	80.21%

Totals
Change from base Build 6466099147:	0.01%
Covered Lines:	8934
Relevant Lines:	10911

---

💛 - Coveralls

[njtran]

good catch! Just some nits on the tests.

[njtran]

approved with comments nits