[release-0.25] Update osInfo annotation on Cluster resource during cluster upgrade

[anujc25]

What this PR does / why we need it

• This changes updates osInfo annotation on the cluster resource during
  cluster upgrade

Signed-off-by: Anuj Chaudhari anujc@vmware.com

Which issue(s) this PR fixes

Fixes #3090

Describe testing done for PR

• Added unit tests for patch operations

Manual testing:

• Create workload cluster with OS_NAME: amazon
• Verified the osInfo annotation on the cluster resource
• Upgrade the workload cluster with --os-name ubuntu
• Cluster was upgraded successfully
• Verified the annotation on the cluster resource and it was updated to specify ubuntu,20.04,amd64

Release note

Fixed `osInfo` annotation in Cluster CR is not correct after upgrade workload cluster with another os

Additional information

Special notes for your reviewer

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3092/20220805182438/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-0.25@a0ff565). Click here to learn what that means.
The diff coverage is n/a.

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[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3092/20220807233137/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[vuil]

lgtm