Add unit test for "Look" in Looker source

[tuliren]

Tell us about the problem you're trying to solve

• Add follow up tests for 🎉 Source Looker: add run-look endpoint #3911.

Describe the solution you’d like

• We need to create a "Look" in our looker sandbox and reference its ID in our tests for this feature to be tested consistently.

Describe the alternative you’ve considered or used

N/A

Additional context

N/A

Are you willing to submit a PR?

N/A