Add Cassandra 4.1.6 to the build matrix

[emerkle826]

Fixes #527

[burmanm]

question: I wonder if we'll start needing separate 4.1 smoke tests soon? So that 4.1.2, 4.1.3, 4.1.6 work as they have different paths.

[emerkle826]

question: I wonder if we'll start needing separate 4.1 smoke tests soon? So that 4.1.2, 4.1.3, 4.1.6 work as they have different paths.

I was thinking about that. What I want to do is have LifecycleIT run against the different versions as it should flush out these kinds of issues. I would really appreciate upstream not making some of these types of internal changes within a major-minor release, but they are internal bits that are normally not exposed, so it is what it is.

[emerkle826]

question: I wonder if we'll start needing separate 4.1 smoke tests soon? So that 4.1.2, 4.1.3, 4.1.6 work as they have different paths.

@burmanm I added 2c35302 to test 4.1.2 and 4.1.5 to make sure we don't break things there.