feat: CI tooling for asdf plugins which checks for asdf core banned_commands

Provide asdf plugin authors with the ability to utilise the asdf banned commands list in their CI: https://github.com/asdf-vm/asdf/blob/master/test/banned_commands.bats

Start by reading the asdf core test/banned_commands.bats file linked in the issue and inspect the existing GitHub Actions in this repository. Determine how plugin authors would invoke the check in CI and what output or failure behavior is expected. Done means a documented CI mechanism can check plugins against the asdf banned commands list.

Written by the indexing model from the issue text.