- Upgrade to 0.9.0.
- Replace CFLAGS/LDFLAGS hacks with disabling makepkg's LTO (it wasn't
  effective, anyway).
- Remove unused `native-zlib` feature.
- Override cargo profile flags to enable debug symbols and LTO.
- Change to be closer to our Rust package guidelines.

From https://github.com/mozilla/sccache/blob/main/LICENSE