Add curl for notebook testing

[raydouglass]

Description

Adds curl as a notebook dependency which is used in two notebooks: notebooks/nyc_taxi_years_correlation.ipynb & notebooks/ZipCodes_Stops_PiP_cuSpatial.ipynb (https://github.com/search?q=repo%3Arapidsai%2Fcuspatial+curl&type=code).

This is similar to rapidsai/cugraph#3918 and will fix errors in the notebooks tests in rapidsai/docker.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.