[IMPROVEMENT] Improve log level for resource update failure able to reconcile again

[innobead]

Is your improvement request related to a feature? Please describe (👍 if you like this request)

We should change the log from error to debug instead if the resource change can be reconciled again to prevent any misunderstanding, especially for the object has been modified; please apply your changes to the latest version and try again

#6641 (comment)

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[PhanLe1010]

Sorry. I thought that this one is still assigned to me so I pushed the PR longhorn/longhorn-manager#2211

If you don't mind, I can continue on this one @mantissahz

cc @innobead

[longhorn-io-github-bot]

Pre Ready-For-Testing Checklist

• Where is the reproduce steps/test steps documented?
  The reproduce steps/test steps: Sometime we see this error the object has been modified; please apply your changes to the latest version and try again at log level error in some support bundle. Maybe you can get support bundle from some test pipeline to double-check. The expectation is that the log level should be debug

• Is there a workaround for the issue? If so, where is it documented?
  The workaround is at:

• Does the PR include the explanation for the fix or the feature?

• Does the PR include deployment change (YAML/Chart)? If so, where are the PRs for both YAML file and Chart?
  The PR for the YAML change is at:
  The PR for the chart change is at:

• Have the backend code been merged (Manager, Engine, Instance Manager, BackupStore etc) (including backport-needed/*)?
  The PR is at Improve log level for reconcilidation error longhorn-manager#2211

• Which areas/issues this PR might have potential impacts on?
  Area Logging
  Issues

• If labeled: require/LEP Has the Longhorn Enhancement Proposal PR submitted?
  The LEP PR is at

• If labeled: area/ui Has the UI issue filed or ready to be merged (including backport-needed/*)?
  The UI issue/PR is at

• If labeled: require/doc Has the necessary document PR submitted or merged (including backport-needed/*)?
  The documentation issue/PR is at

• If labeled: require/automation-e2e Has the end-to-end test plan been merged? Have QAs agreed on the automation test case? If only test case skeleton w/o implementation, have you created an implementation issue (including backport-needed/*)
  The automation skeleton PR is at
  The automation test case PR is at
  The issue of automation test case implementation is at (please create by the template)

• If labeled: require/automation-engine Has the engine integration test been merged (including backport-needed/*)?
  The engine automation PR is at

• If labeled: require/manual-test-plan Has the manual test plan been documented?
  The updated manual test plan is at

• If the fix introduces the code for backward compatibility Has a separate issue been filed with the label release/obsolete-compatibility?
  The compatibility issue is filed at

[nitendra-suse]

Verified Pass on longhorn master

longhorn-manager.log output:

2023-11-15T00:59:09.387348844Z time="2023-11-15T00:59:09Z" level=debug msg="Failed to syncing ConfigMap" func=controller.handleReconcileErrorLogging file="utils.go:70" ConfigMap=longhorn-system/longhorn-default-setting controller=longhorn-kubernetes-configmap-controller error="failed to sync config map longhorn-system/longhorn-default-setting: failed to update built-in settings with customized values: Operation cannot be fulfilled on settings.longhorn.io "default-replica-count": the object has been modified; please apply your changes to the latest version and try again" node=ip-10-0-2-10