Using SubType::Custom to generate a partition table causes panic when flashing

[cs-clarence]

Using SubType::Custom when generating a partition table causes panic when flashing:

Partition::new(
  "fs",
  Type::Data,
  SubType::Custom(0x83), // littlefs 
  0x810_000, // App offsets must be multiples of 0x10000 (64KB)
  0x600_000,
  false,
);

a snippet used to generate a partition table file

Unfortunately, panic occurs when flashing:

Error:   × Main thread panicked.
  ├─▶ at /home/rencedm112/.cargo/registry/src/index.crates.io-6f17d22bba15001f/esp-idf-part-0.4.1/src/partition/mod.rs:171:56
  ╰─▶ called `Option::unwrap()` on a `None` value
  help: set the `RUST_BACKTRACE=1` environment variable to display a backtrace.

The panic occurs here:

/// Create a [SubType::Data] variant from an integer value
pub fn data(value: u8) -> Self {
    Self::Data(DataType::from_repr(value as usize).unwrap())
}

the panic occurs because 0x832 subtype is not recognized, which causes DataType::from_repr() to return Option::None