GH-132983: Use a standard autoconf version check for zstd

[AA-Turner]

cc @ned-deily, it seems that this works & is simpler? I'll run buildbots.

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• Issue: Implement PEP 784 - Adding Zstandard to the Python standard library #132983

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @AA-Turner for commit afbc562 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F133479%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

[ned-deily]

@AA-Turner That looks promising: it seems to handle my use case. Thanks!

cc: @emmatyping

[ned-deily]

... and the ghcr.io/cirruslabs/macos-runner:sonoma runner also now appears to successfully build _zstd.

[emmatyping]

Thanks! I didn't know this was something one could do. TIL

I'd like to wait for a RHEL8 buildbot to go green before merging to ensure that it works when there is a version of libzstd that is too old. Otherwise it looks much better.

[emmatyping]

And thank you for catching the original issue @ned-deily !

[ned-deily]

I didn't know this was something one could do.

There is always something in Autotools that no one knows you can do.

[AA-Turner]

https://buildbot.python.org/#/builders/170/builds/1765

checking for libzstd >= 1.4.5... no
checking for zstd.h... no
checking for zdict.h... no
...
checking for stdlib extension module _zstd... missing

Seems to work.

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