feat: Generate different dependencies in `Cargo.toml` for `guest` and `host` apps for `SP1`

[merembablas]

Is it possible to generate or select different dependencies in Cargo.toml for guest and host apps for SP1?

my zkRust codes has a dependency on reqwest, which can be built on the guest app but fails to build on the host app due to dependencies on OpenSSL or Rustls.