feat: 🎸 Add --zones and --exclude flag to fetch_gcp

[sunny0826]

✅ Closes: #2555

Add --zones and --exclude flag to fetch_gcp.

--zones: Fetch the list of specified zones.
--exclude: Exclude the list of specified regions.

[iojw]

Thank you @sunny0826 for the contribution again! Left some comments.

[iojw]

python sky/clouds/service_catalog/data_fetchers/fetch_gcp.py --zones us-west2-a will throw an error because df is empty.

You may need to add the empty dataframe check to get_gpu_df and potentially get_vm_df as well. Could you test for similar bugs like this and fix them?

[sunny0826]

python sky/clouds/service_catalog/data_fetchers/fetch_gcp.py --zones us-west2-a will throw an error because df is empty.

You may need to add the empty dataframe check to get_gpu_df and potentially get_vm_df as well. Could you test for similar bugs like this and fix them?

I realized that only the relevant GPU information was not found in that Zone, not the VM information, so I added the check to get_gpu_df and threw an error.

[iojw]

If there are no GPUs for a given zone, I think we still want to include both the VM and TPU information, instead of erroring.

[sunny0826]

Well, I added checks to both get_gpu_df and get_vm_df.

[iojw]

Thank you for the effort @sunny0826! This is good to go (just made a minor edit for the comments as discussed).