Bump weezl to 0.2 (faster decode + multiple LZW fixes; fixes small interlaced GIFs, supersedes #232 + #233)

[lilith]

weezl 0.2.x is a substantial step up from the 0.1.x line this crate currently pins, on both correctness and speed.

Correctness — 0.2.x fixes several decoder bugs over 0.1.10

• Small output buffers no longer produce an erroneous NoProgress when progress was only filling the internal word buffer (yield_on_full + small output buffer: false NoProgress loses data weezl#68, fixed by fix: yield_on_full correctness on wuffs branch (#68) weezl#72) — streaming/abstraction decoders could previously silently drop data.
• An initial code size of 12 no longer fails to detect some malformed streams that could panic or emit malformed output (test: regression for derive_burst OOB on bit-flipped input weezl#64).
• 0- and 1-bit data sizes are now fully supported (feat: support min_code_size 0 and 1 weezl#67, Rename decoder and options #78).
• 0.2.1 additionally fixes a bug that overwrote some initial dictionary entries in streams that don't emit a clear code before the dictionary fills.

The #68 fix is the one that matters here: it's exactly what made small interlaced GIFs fail to decode. When read_into_buffer hands weezl a tiny per-row output slice (7–47 bytes for a small interlaced frame), weezl 0.1.x could return NoProgress even though it had advanced its internal word buffer, and the streaming decoder then treated the still-valid input as truncated. On weezl 0.2.1 that no longer happens, so no decoder-side handling is needed — the bump alone fixes it.

Performance

weezl 0.2.0 reworked the decoder around a Wuffs-inspired design (image-rs/weezl#77) that decodes 8 bytes at a time over a pre-built code tree. I measured decode through this crate's full path (master, the only change being the weezl version), interleaved A/B across an 8×8→2048×2048 size sweep on two architectures (x86-64 Zen 4 and aarch64 Neoverse-N1):

On GIFs larger than 16×16, weezl 0.2.1 decodes faster — roughly +7% at 32×32 rising to +24% at 2048×2048 on x86-64, and +9% rising to +32% on aarch64 (about 1.24× / 1.32× per pixel at large sizes; the win grows with image size, and aarch64 benefits most). The interlaced regression GIFs below also now decode correctly where 0.1.10 rejected them.

(Numbers are interleaved-A/B ratios via zenbench, no target-cpu=native; bench notes available on request.)

What this changes

• weezl dependency 0.1.10 → 0.2.1.
• MSRV 1.85 → 1.88 (weezl 0.2.1 declares rust-version = "1.88.0" — see reviewer note).
• Adds tests/small_interlaced.rs: regression tests for 7×7, 9×9, and 47×63 interlaced GIFs produced by gifsicle 1.95 (valid per GIF89a, verified with giftopnm), which previously failed with DecodingFormatError { underlying: "unexpected data" }.

No source changes are required in src/reader/decoder.rs: the LzwReader wrapper already consumes weezl's BufferResult/VectorResult shape, which is unchanged between 0.1.10 and 0.2.1. The entire non-test diff is the two Cargo.toml version strings.

Supersedes #232 and #233

• test: regression tests for small interlaced GIF decode failure #232 added these same tests/small_interlaced.rs cases as failing tests (no fix); they're included here and now pass.
• fix: handle weezl NoProgress on small interlaced GIF output buffers #233 proposed an lzw_drain_one decoder-side workaround; with weezl 0.2.1 the decoder no longer stalls, so the workaround is unnecessary.

Both #232 and #233 can be closed in favour of this PR. A/B on a clean master:

Config	small_interlaced result
master + weezl 0.1.10	3 failed (unexpected data)
master + weezl 0.2.1 (this PR)	3 passed

Full cargo test is green on the bumped tree.

Reviewer note: MSRV

weezl 0.2.1 raises its MSRV to Rust 1.88.0. image-gif currently declares rust-version = "1.85", so this PR also bumps the declared MSRV to 1.88. If holding MSRV at 1.85 is a hard requirement, this bump can't land as written — that's the trade-off to weigh. For reference, image-tiff already took the same step on main (image-rs/image-tiff#392 bumped weezl to 0.2 and MSRV to 1.88.0).

Refs: image-rs/weezl#64, #67, #68, #72, #77, #78, and #232, #233.

[kornelski]

CI needs msrv update

[lilith]

I just found out that Ubuntu 26.04 LTS bundles Rust 1.93.1