Unable to search for only the stable versions

[nyurik]

I noticed this in the changelog:

`--start` and `--end` now support git tags (like `1.59.0`) to bisect between stable releases.

which implies that if i specify start and end as proper versions, cargo-bisect won't even download nightly builds, yet when I ran it with cargo bisect-rustc --start 1.67.0 --end 1.84.0 --preserve --script ../test.sh it began downloading nightly builds. The currently installed version is v0.6.9