the `-rie` arguments of `sed` were probably meant as `-r -i -e`,
however, due to the way it was written it ended up being `-r -i e`, thus
causing `-i` (edit in-place) to generate backup files. so for every
edited `Cargo.toml` it also created a `Cargo.tomle` with the previous
content.

`-e` is anyway not needed as the last argument of `sed` here is the
expression to be executed.