bug: non-copyable types are disabled from dictionaries values

[enitrat]

Bug Report

Cairo version:
2.3.1

Current behavior:
Running the following code compiles fine, but running it results in this error:

   Compiling dict_array v0.1.0 (/Users/msaug/cairo_projects/dict_array/Scarb.toml)
thread 'main' panicked at /Users/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/cairo-lang-sierra-generator-2.3.0/src/db.rs:194:6:
Got failure while specializing type.: TypeSpecialization { type_id: GenericTypeId("Felt252Dict"), error: UnsupportedGenericArg }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: `scarb metadata` exited with error

Expected behavior:
The code compiles and runs finefine .

Steps to reproduce:

Related code:

use dict::{felt252_dict_entry_get, felt252_dict_entry_finalize};
fn main() -> felt252 {
    let mut dict: Felt252Dict<Nullable<Array<felt252>>> = Default::default();
    let arr = array![0x1, 0x2, 0x3];

    dict.insert(1, NullableTrait::new(arr));
    let (entry, value) = dict.entry(1);
    let mut val = value.deref();
    *val[0]
}

Other information:

[orizi]

Solved on 2.4.0-rc0 - will be merged into main upon starknet mainnet release.