eliminate cargo make as a host dependency

## Description

With #14, `twoliter make` will be able to build bottlerocket so long as `cargo make` is available on the host. Eliminate this requirement.

Possibilities
- Use `cargo make` as a library.
- Embed `cargo make` as a binary in the tarball and install it
- Port all Makefile.toml functionality to native Rust functions (this would be ideal, but may take some time)

## Definition of Done

When using Twoliter to build a Bottlerocket image no longer requires `cargo make` on the host.

Prerequisite

- [x] #14

Start by reviewing the `twoliter make` behavior introduced by prerequisite #14 and the role of `cargo make` in building Bottlerocket. Evaluate the listed library, embedded-binary, and native-Rust approaches; done means Twoliter can build a Bottlerocket image without `cargo make` installed on the host.

Written by the indexing model from the issue text.