Bug#1053940: python-cooler: test failure with pandas 2.1

[Rebecca N. Palmer]

Package: src:python-cooler
Version: 0.9.1-1
Control: block 1043240 by -1
python-cooler fails its autopkgtest with pandas 2.1, currently in 
experimental.

Log:
https://ci.debian.net/data/autopkgtest/unstable/amd64/p/python-cooler/38997833/log.gz

A common source of failures is new pandas FutureWarnings in tests that 
are set to fail on unexpected warnings.