CompatHelper: bump compat for "LearnBase" to "0.5"

[github-actions[bot]]

This pull request changes the compat entry for the LearnBase package from 0.2, 0.3 to 0.2, 0.3, 0.5.

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.