Error in `examples/spatial/malaria_prevalence.ipynb`

Something up with the CRS using these versions:

rasterio.__version__
# '1.4.2'
pyproj.__version__
# '3.7.0'
mapclassify.__version__
# '2.8.1'

Here is the tracback:

──────────────────────────────────────────── Error running examples/spatial/malaria_prevalence.ipynb ─────────────────────────────────────────────

---------------------------------------------------------------------------
Exception encountered at "In [7]":
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[7], line 13
      9 with rio.open(in_path) as src:
     11     img = src.read()
---> 13     src_crs = src.crs["init"].upper()
     14     min_lon, min_lat, max_lon, max_lat = src.bounds
     15     xs = gambia_gpdf_4326["geometry"].x

File rasterio/crs.pyx:885, in rasterio.crs.CRS.__getitem__()

KeyError: 'init'

Open examples/spatial/malaria_prevalence.ipynb and inspect cell In [7], especially the CRS access after opening the raster. Reproduce the failure with rasterio 1.4.2, pyproj 3.7.0, and mapclassify 2.8.1, then verify that the notebook runs successfully and produces the expected spatial output.