`lib`: BLOCKED) Add `<{BITS}>` to the type when Display works

*On 2026-08-31 @decofe wrote in [`a9450b4`](https://github.com/alloy-rs/ruint/commit/a9450b499c03f259238c2955b9512de873a77e12) “chore: apply latest nightly rustfmt (#627)”:*

BLOCKED) Add `<{BITS}>` to the type when Display works
in const fn.

```rust
#[inline(always)]
#[must_use]
#[track_caller]
pub const fn from_limbs(limbs: [u64; LIMBS]) -> Self {
if Self::SHOULD_MASK {
// FEATURE: (BLOCKED) Add `<{BITS}>` to the type when Display works
// in const fn.
assert!(
limbs[LIMBS - 1] <= Self::MASK,
"Value too large for this Uint"
);
}

```
*From [`src/lib.rs:245`](https://github.com/alloy-rs/ruint/blob/a9450b499c03f259238c2955b9512de873a77e12/src/lib.rs#L245)*

Start at src/lib.rs:245 and inspect the from_limbs const fn assertion. Research the Rust limitation around using Display in const fn, then determine whether the blocked constraint has changed. Done means the error text includes the Uint bit width without breaking const evaluation.

索引モデルが issue の本文から書いたものです。