As reported in https://github.com/dbrgn/tealdeer/issues/244, some users
on macOS had problems with `rustls-tls-native-roots`. Since we did not
find the root cause of this, we'll build macOS release builds with
`rustls-tls-webpki-roots` instead.
Fixes#244.
- Clean up scripts
- Create draft release before uploading assets
- Find release for current tag, don't simply pick the latest
- Add Windows builds
- Add checksums for binaries