Test failures with pyshp 3.0.0 (AttributeError: 'tuple' object has no attribute 'tolist')

As reported in Debian Bug #1110711, a few tests fail with pyshp 3.0.0:

Traceback (most recent call last):
  File "/tmp/autopkgtest-lxc.j0rpiwrc/downtmp/autopkgtest_tmp/hurrtracks.py", line 17, in <module>
    shp_info = m.readshapefile('huralll020','hurrtracks',drawbounds=False)
  File "/usr/lib/python3/dist-packages/mpl_toolkits/basemap/__init__.py", line 2152, in readshapefile
    bbox = shf.bbox.tolist()
           ^^^^^^^^^^^^^^^
AttributeError: 'tuple' object has no attribute 'tolist'

Full output: https://ci.debian.net/packages/b/basemap/unstable/amd64/62754867/

From the pyshp README:

bbox, mbox and zbox attributes are all new Namedtuples.