Update notebooks to switch to new urls

[slesaad]

Description

We recently migrated to using the earth.gov/ghgcenter/api* URLs.

The notebooks in this repository still point to the old URLs ghg.center/api*

ghg.center/api/stac -> earth.gov/ghgcenter/api/stac ghg.center/api/raster -> earth.gov/ghgcenter/api/raster

AC

• [x] All the notebooks updated with the new urls