register_fn_with_ctx does not supply context for async functions

[kilesduli]

Minimal reproduction:

  use steel::{
      SteelVal,
      steel_vm::{engine::Engine, register_fn::RegisterFn},
  };

  async fn add_with_context(ctx: i32, value: i32) -> i32 {
      ctx + value
  }

  fn main() {
      let mut engine = Engine::new();

      engine.register_value("*ctx*", SteelVal::IntV(10));
      engine.register_fn_with_ctx(
          "*ctx*",
          "add-with-context",
          add_with_context,
      );

      let result = engine.run("(add-with-context 1)");
      println!("{result:?}");
  }

Err(SteelErr { repr: Repr { kind: ArityMismatch, message: "add-with-context expected 2 argument, got 1", span: Some(1..17), stack_trace: Some(DehydratedStackTrace { stack_trace: [] }) } })

Seems supply_context_arg in impl RegisterValue for Engine only handle SteelVal::BoxedFunction

steel/crates/steel-core/src/steel_vm/engine.rs

Lines 437 to 454 in 3a418c9

	impl RegisterValue for Engine {
	fn register_value_inner(&mut self, name: &str, value: SteelVal) -> &mut Self {
	let idx = self.virtual_machine.compiler.write().register(name);
	self.virtual_machine.insert_binding(idx, value);
	self
	}
	fn supply_context_arg(&mut self, ctx: &'static str, name: &'static str) -> &mut Self {
	if let Ok(existing) = self.extract_value(name) {
	if let SteelVal::BoxedFunction(f) = &existing {
	let func = generate_function(self, &SteelString::from(ctx), &existing, f);
	self.register_value(name, func);
	}
	}
	self
	}
	}