Remove unused Rustyline dependency

[SpaceManiac]

Starstream's attempt to depend on zkEngine on a wasm32 target results in a devious Cargo dependency resolution failure pointing to the rustyline crate. But zkEngine doesn't actually use rustyline, so the problem can be solved by removing it from the dependency list.

[SpaceManiac]

Error detail:

thread 'main' panicked at src/tools/cargo/src/cargo/core/resolver/features.rs:325:13:
did not find features for (PackageId { name: "rustyline", version: "13.0.0", source: "registry `crates-io`" }, NormalOrDev) within activated_features:
[
    <...snip description of every crate in the dependency tree...>
]
stack backtrace:
   0: rust_begin_unwind
             at /rustc/6650252439d4e03368b305c42a10006e36f1545e/library/std/src/panicking.rs:695:5
   1: core::panicking::panic_fmt
             at /rustc/6650252439d4e03368b305c42a10006e36f1545e/library/core/src/panicking.rs:75:14
   2: <cargo::core::resolver::features::ResolvedFeatures>::activated_features
   3: cargo::core::compiler::unit_dependencies::new_unit_dep_with_profile
   4: cargo::core::compiler::unit_dependencies::new_unit_dep
   5: cargo::core::compiler::unit_dependencies::compute_deps
   6: cargo::core::compiler::unit_dependencies::deps_of
   7: cargo::core::compiler::unit_dependencies::deps_of
   8: cargo::core::compiler::unit_dependencies::deps_of
   9: cargo::core::compiler::unit_dependencies::deps_of_roots
  10: cargo::core::compiler::unit_dependencies::build_unit_dependencies
  11: cargo::ops::cargo_compile::create_bcx
  12: cargo::ops::cargo_compile::compile_ws
  13: cargo::ops::cargo_compile::compile_with_exec
  14: cargo::ops::cargo_compile::compile
  15: cargo::commands::build::exec
  16: <cargo::cli::Exec>::exec
  17: cargo::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.