A package manager written in Rust for a language designed to be embedded in C and which relies heavily on C libraries, and also configured in TOML when Lua itself was created to be used as a configuration language in C programs?

No, thanks.

Luarocks has its limits and probably should be rewritten, but using a language that fits the ecosystem and following the culture of the Lua ecosystem.

Rust and Cargo represent exactly the opposite of Lua.