Compile compression.zstd as added in CPython 3.14

[agriyakhetarpal]

Description

xref #6233, #6033, #5995. This PR adds the compression.zstd module which is now available in Python 3.14, but we weren't including it.

I caught this while working on zarr-developers/numcodecs#529 locally as part of a dependency that used the module, but I couldn't import it.

Checklist

• Add a CHANGELOG entry
• Add / update tests
• Add new / update outdated documentation

[agriyakhetarpal]

Okay, this is passing in the test-core- tests for the trio of Chrome, Firefox, and Node.

I guess I just need to update the CHANGELOG, but maybe we should also document that we should periodically look at https://github.com/python/cpython-source-deps and update it too, to stay in sync with CPython. I'll do in my evening later today, but till that time, this is ready for review. Thanks!

[ryanking13]

So it looks like this adds ~10KB to asm.mjs and ~200KB to asm.wasm (compressed). It is not a blocker for this PR, but maybe worth remembering.

- pyodide.asm.mjs:
    Original size: 1170 KB
    Gzip compressed size (level 1): 292 KB
    Gzip compressed size (level 6): 245 KB
    Gzip compressed size (level 9): 245 KB
    Brotli compressed size: 195 KB
- pyodide.asm.wasm:
    Original size: 8934 KB
    Gzip compressed size (level 1): 3750 KB
    Gzip compressed size (level 6): 3331 KB
    Gzip compressed size (level 9): 3322 KB
    Brotli compressed size: 2571 KB

- pyodide.asm.mjs:
    Original size: 1241 KB
    Gzip compressed size (level 1): 304 KB
    Gzip compressed size (level 6): 255 KB
    Gzip compressed size (level 9): 255 KB
    Brotli compressed size: 202 KB
- pyodide.asm.wasm:
    Original size: 9640 KB
    Gzip compressed size (level 1): 3986 KB
    Gzip compressed size (level 6): 3530 KB
    Gzip compressed size (level 9): 3517 KB
    Brotli compressed size: 2708 KB

[ryanking13]

Thanks! Could you check the gha failure? I don't think it is related to this PR, but it seems like GHA or conda changed something recently, making the build fail.

[agriyakhetarpal]

Thanks! Fixed in #6241.

I think we can go further and reduce the size a bit. Let me try!

[agriyakhetarpal]

Our size-checking script reports no size increase because we report it in KB and it rounds off the increase, effectively hiding it. So I checked: I downloaded pyodide-core.tar.gz from main and the one from here and updated the script to check with higher granularity (will update in a separate PR), and we get:

on main (061a9d0) at the time of writing

- pyodide.asm.mjs:
    Original size: 1,198,477 bytes (1170.39 KB)
    Gzip compressed size (level 1): 299,914 bytes (292.88 KB)
    Gzip compressed size (level 6): 251,707 bytes (245.81 KB)
    Gzip compressed size (level 9): 251,526 bytes (245.63 KB)
    Brotli compressed size: 200,678 bytes (195.97 KB)
- pyodide.asm.wasm:
    Original size: 9,149,350 bytes (8934.91 KB)
    Gzip compressed size (level 1): 3,840,709 bytes (3750.69 KB)
    Gzip compressed size (level 6): 3,411,795 bytes (3331.83 KB)
    Gzip compressed size (level 9): 3,401,934 bytes (3322.20 KB)
    Brotli compressed size: 2,630,679 bytes (2569.02 KB)
- python_stdlib.zip:
    Original size: 2,552,031 bytes (2492.22 KB)
    Gzip compressed size (level 1): 2,512,287 bytes (2453.41 KB)
    Gzip compressed size (level 6): 2,509,781 bytes (2450.96 KB)
    Gzip compressed size (level 9): 2,509,727 bytes (2450.91 KB)
    Brotli compressed size: 2,493,672 bytes (2435.23 KB)

here, after adding the zstd build and after enabling the MinSizeRel build + removing legacy zstd support

- pyodide.asm.mjs:
    Original size: 1,246,605 bytes (1217.39 KB)
    Gzip compressed size (level 1): 308,489 bytes (301.26 KB)
    Gzip compressed size (level 6): 259,000 bytes (252.93 KB)
    Gzip compressed size (level 9): 258,860 bytes (252.79 KB)
    Brotli compressed size: 206,235 bytes (201.40 KB)
- pyodide.asm.wasm:
    Original size: 9,610,091 bytes (9384.85 KB)
    Gzip compressed size (level 1): 3,998,661 bytes (3904.94 KB)
    Gzip compressed size (level 6): 3,549,976 bytes (3466.77 KB)
    Gzip compressed size (level 9): 3,536,690 bytes (3453.80 KB)
    Brotli compressed size: 2,741,612 bytes (2677.36 KB)
- python_stdlib.zip:
    Original size: 2,552,062 bytes (2492.25 KB)
    Gzip compressed size (level 1): 2,512,337 bytes (2453.45 KB)
    Gzip compressed size (level 6): 2,509,843 bytes (2451.02 KB)
    Gzip compressed size (level 9): 2,509,798 bytes (2450.97 KB)
    Brotli compressed size: 2,493,736 bytes (2435.29 KB)

So we now add 8.38 KB (was ~11 KB) to asm.js and 108 KB (was ~195 KB) to asm.wasm compressed, which is much better.

[ryanking13]

Awesome. Thanks!