tarantool::fiber::Fiber memory leak

Environment

Release / Commit: tarantool v 1.1.0

OS: Ubuntu 22.04 LTS

Rust version: 1.71

Steps to Reproduce

1. Create test tarantool project. lib.rs:

use std::os::raw::c_int;
use std::time::Duration;
use tarantool::fiber;
use tarantool::fiber::Fiber;
use tarantool::tuple::{FunctionArgs, FunctionCtx};

#[no_mangle]
pub extern "C" fn easy(ctx: FunctionCtx, args: FunctionArgs) -> c_int {
    for _ in 0..10_000_000 {
        let mut ack_fiber = Fiber::new(&format!("ack_{}", tarantool::uuid::Uuid::random()), &mut |b: Box<(String, String)>| {
            fiber::sleep(Duration::from_millis(10));
            if &(*b).0 == &(*b).1 {
                println!("unreachable");
            }
            0
        });
        ack_fiber.set_joinable(false);
        ack_fiber.start(("str 1 2 3 4".to_string(), "str 4 5 6 7".to_string()));
        fiber::sleep(Duration::from_millis(1));
    }

    ctx.return_mp(&()).unwrap();
    0
}

2. init.lua:

require('easy')
box.cfg({listen = 3301})

box.schema.func.create('easy', {language = 'C', if_not_exists = true})
box.schema.user.grant('guest', 'execute', 'function', 'easy', {if_not_exists = true})

function my_fn()
    local v = box.func.easy:call()
    print(v)
end

box.func.easy:call()

3. Check htop, i got ~2mb leak per min.