Update vendored double-conversion to 3.2.1

[joemarshall]

Ultrajson doesn't build on webassembly (e.g. pyodide) because the version of double-conversion used is too old. This updates it to a newer version which supports webassembly.

[codecov-commenter]

Codecov Report

Merging #570 (ffe12ed) into main (13da58c) will not change coverage.
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[joemarshall]

About this - It needs webassembly tests adding, I can do this once a PR to pytest-pyodide (pyodide/pytest-pyodide#59 )is added to make it possibly to skip non-pyodide tests

[bwoodsend]

What would make a test non-pyodide? Any reason we can't just add a few

@pytest.mark.skipif(platform.machine().startswith("wasm"), "Not supported on pyodide")

statements instead (assuming there's not a better way to detect if running on pyodide)?

[joemarshall]

@bwoodsend pyodide uses a custom pytest plugin which assumes you're writing tests to run things in pyodide. It means you can do things like spin up servers for pyodide code in a browser to talk to. But right now there's no way to just run normal pytest tests on pyodide. It would need to spin up a browser+pyodide for each test or for each module of tests or something, and then run the tests in there automatically.

At the moment if you want pyodide tests, you have to write a custom test_pyodide.py for your project which wraps the project tests and calls them in pyodide.

[bwoodsend]

Okay, fair enough. I'll merge this now since it's only updating double-conversion (which we really ought to be more proactive in keeping up to date anyway) and keep any mention of supporting WASM out of the changelog until the tests go in.

[joemarshall]

@bwoodsend Any chance of a release to pypi to get this version onto pypi and save me build pain...

[bwoodsend]

Release button has been pressed.