skip[fuzz]: allow generation of longer arrays

[joseph-isaacs]

Allow the fuzzer to create longer arrays to exercise more file_io logic (e.g. zone_map partitions).

Adds a new trait ArbitraryWith and ArbitraryArrayConfig to express this.

/// Trait for generating arbitrary values with a caller-provided configuration.
pub trait ArbitraryWith<'a, C>: Sized {
    /// Generate an arbitrary value using the provided configuration.
    fn arbitrary_with_config(u: &mut Unstructured<'a>, config: &C) -> Result<Self>;
}

/// Configuration for arbitrary array generation.
#[derive(Clone, Debug)]
pub struct ArbitraryArrayConfig {
    /// Fixed dtype, or `None` to generate one from [`Unstructured`].
    pub dtype: Option<DType>,
    /// Inclusive range for the total array length.
    pub len: RangeInclusive<usize>,
}

[codspeed-hq]

Merging this PR will degrade performance by 31.49%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 3 improved benchmarks
❌ 6 regressed benchmarks
✅ 1189 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	runend[10M_i32_runlen_1000]	97.3 µs	134.1 µs	-27.48%
❌	WallTime	runend[10M_i32_runlen_10]	161.2 µs	191.7 µs	-15.89%
⚡	WallTime	dynamic_dispatch_u32[10M]	161.8 µs	108.5 µs	+49.06%
❌	WallTime	dynamic_dispatch_u32[10M]	127 µs	185.3 µs	-31.49%
❌	WallTime	10M_10%[1000000]	132.2 µs	169.7 µs	-22.13%
⚡	WallTime	10M_50%[5000000]	308.4 µs	277.2 µs	+11.24%
⚡	WallTime	10M_90%[10000000]	396.1 µs	359.8 µs	+10.08%
❌	WallTime	decompress_kernel[1M]	379.9 µs	427 µs	-11.03%
❌	Simulation	bitwise_not_vortex_buffer_mut[128]	246.1 ns	275.3 ns	-10.6%

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_{Comparing ji/fuzz-arb-longer (d1f7ecd) with develop (128ce5f)}