Run CBMC regression tests with Bitwuzla

[tautschnig]

As discussed in #8365, Bitwuzla may be superior to Z3 in some cases. #8384, however, showed that we don't always use it correctly. We should establish how Bitwuzla compares to Z3 (and CVC5) across all regression tests via a CI job.

[rod-chapman]

I like this idea. This will provide hard data to drive improvement of Bitwuzla and CVC5.