According the repository local hooks section,

local hooks can use any language which supports additional_dependencies or docker_image / fail / pygrep / script / system.

It’s not clear to me which languages can’t be used. For example, the descriptions for both python and ruby don’t explicitly mention that those languages support additional_dependencies, but they do indeed support additional_dependencies. This makes me question whether or not you can create (for example) a local dotnet hook. The description for dotnet doesn’t explicitly say that additional_dependencies is supported, but it also doesn’t say that additional_dependencies isn’t supported.