CompatHelper: bump compat for Turing to 0.31 for package BayesianInference, (keep existing compat)

[github-actions[bot]]

This pull request changes the compat entry for the Turing package from 0.28, 0.30 to 0.28, 0.30, 0.31 for package BayesianInference. This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.