fix: cargo bin dir

[DaRacci]

Use the environment variable to find the dir instead of the hard coded default

[hykilpikonna]

For some reason I don't have the environment variable $CARGO_HOME set up by default, but I do have the directory ~/.cargo/bin. It might be better to have a default fallback if $CARGO_HOME is not set (e.g. use "${CARGO_HOME:-$HOME/cargo}").

[hykilpikonna]

Okay, it should work, thank you for the pull request!