CLI and tools.deps support

Lots of projects now use [tools.deps with the Clojure CLI.](https://clojure.org/guides/deps_and_cli)

Personally, I haven't used leiningen in over a year and avoid uberjar whereever I can (and I very well can with tools.deps!)

If a project has a `deps.edn` it can be run directly (no uberjars needed):
`clj -m my-project.main`

This is a much simpler, lightweight and flexible approach. It would be awesome if heroku supported it, especially given that it looks like the Clojure CLI is already installed by this buildpack.

Start by reviewing the buildpack's existing Leiningen and uberjar flow, then compare it with the Clojure CLI and a project's deps.edn entry point. The expected outcome is support for running a deps.edn project directly with clj -m, without requiring an uberjar.

Written by the indexing model from the issue text.