chore: Fix spurious discovered subnets lines in logging

[jonathan-innis]

Fixes #N/A

Description

This fixes an issue where Karpenter was spurious logging "discovered subnets" any time there was a change in the subnet's IP availability. This change ensures that we will only log subnets when there is a change in the ids that are being selected on.

{"level":"DEBUG","time":"2024-07-10T07:08:41.539Z","logger":"controller","message":"discovered subnets","commit":"ff0dc7d","controller":"nodeclass.status","controllerGroup":"karpenter.k8s.aws","controllerKind":"EC2NodeClass","EC2NodeClass":{"name":"default"},"namespace":"","name":"default","reconcileID":"54da3ce7-88e7-42e3-ad25-6c0d9fef954f","subnets":[{"id":"subnet-0c89532267e680e6f","zone":"us-west-2a","zoneID":"usw2-az1"},{"id":"subnet-09d3d3e0bd7f68ee9","zone":"us-west-2b","zoneID":"usw2-az2"},{"id":"subnet-01095f4c202083b01","zone":"us-west-2a","zoneID":"usw2-az1"},{"id":"subnet-01a75589aa6237be1","zone":"us-west-2b","zoneID":"usw2-az2"},{"id":"subnet-060f9fb17941d125c","zone":"us-west-2c","zoneID":"usw2-az3"},{"id":"subnet-0e60f26cf52c5a6df","zone":"us-west-2c","zoneID":"usw2-az3"}]}
{"level":"DEBUG","time":"2024-07-10T07:12:45.409Z","logger":"controller","message":"discovered subnets","commit":"ff0dc7d","controller":"nodeclass.status","controllerGroup":"karpenter.k8s.aws","controllerKind":"EC2NodeClass","EC2NodeClass":{"name":"default"},"namespace":"","name":"default","reconcileID":"6cc09a98-b64f-42a7-b8b2-3f6a37ea1448","subnets":[{"id":"subnet-01095f4c202083b01","zone":"us-west-2a","zoneID":"usw2-az1"},{"id":"subnet-01a75589aa6237be1","zone":"us-west-2b","zoneID":"usw2-az2"},{"id":"subnet-060f9fb17941d125c","zone":"us-west-2c","zoneID":"usw2-az3"},{"id":"subnet-0e60f26cf52c5a6df","zone":"us-west-2c","zoneID":"usw2-az3"},{"id":"subnet-0c89532267e680e6f","zone":"us-west-2a","zoneID":"usw2-az1"},{"id":"subnet-09d3d3e0bd7f68ee9","zone":"us-west-2b","zoneID":"usw2-az2"}]}

How was this change tested?

make presubmit

Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: #
• No

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

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[coveralls]

Pull Request Test Coverage Report for Build 9869887590

Details

• 4 of 4 (100.0%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.01%) to 79.025%

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Files with Coverage Reduction	New Missed Lines	%
pkg/providers/amifamily/ami.go	1	93.33%

Totals
Change from base Build 9865052861:	-0.01%
Covered Lines:	5968
Relevant Lines:	7552

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💛 - Coveralls