[CI] Run Python tests with dev version of RAPIDS

[hcho3]

In #11066, I disabled tests with nightly RAPIDS. We should bring it back so that we can catch errors like #11324 early in the development cycle.

Note: Tests with nightly RAPIDS should be hosted in a separate CI pipeline, so that failures with nightly RAPIDS doesn't immediately block daily development work. What's important is to detect breakages early.