Fix breaking changes in chainladder-python from pandas 2.0

[cbalona]

Several breaking changes were introduced with pandas 2.0 that causes most tests to fail.

[Adam-Hoelscher]

The changed need to tryangle for this were pretty easy. Unfortunately, chainladder had a regression due to a change in the sparse package. Next version of chainladder will definitely resolve this, as the PR was merged.

We could make the whole thing work by adding sparse<0.16 to the dependencies for tryangle or we can wait for the next version of chainladder.