Fixing the errors coming up in the pydantic branch

[bcdurak]

• There was a mismatch between the output signature of a step and the input signature of the next step.
• Steps are being imported, even in the local case. I moved the import sky within the step, so it will not fail for people trying the template locally without skypilot.

[avishniakov]

Is it the same as before? Looks identical to #18