chore: pin Ubuntu version for some jobs

[dsharma-dc]

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Why is this PR required? What issue does it fix?: Workaround till medyagh/setup-minikube#565 is fixed

What this PR does?: Pins Ubuntu version on github runner for some jobs

Does this PR require any upgrade changes?: No

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Checklist:

• Fixes #
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[dsharma-dc]

Fixes #355