feat(ci): skip smoke-test lint if there are no changes

[hsheth2]

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[anshbansal]

Approved assuming that any lint failure will cause no docker builds to be triggerred. That is an intentional change to control cost + make CI experience better for all PRs

[hsheth2]

@anshbansal yup that's what this does - lint is still a blocking step, but only runs if there were changes