This change adds two things to our remote server build
process:
1. It now checks if all required tooling is installed before using it or installing it on demand. This includes checks for `rustup` and `cargo-zigbuild` in your `PATH`.
2. Next, if `ZED_BUILD_REMOTE_SERVER` contains `musl` and `ZED_ZSTD_MUSL_LIB`
is set, we will pass its value (the path) to `cargo-zigbuild` as `-C
link-arg=-L{path}`.
Release Notes:
- N/A
fdf5bf7e6a