Release refinement

[hugovk]

Some updates to the release checklist, I followed these for 9.5.0.

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First, I moved the git push --all from near the start (after removing .dev0 from the version and updating CHANGES.rst), to near the end (after incrementing and adding .dev0 to the version).

The reason: the CI does a lot of building during releases and there's a lot of waiting around for the release manager. We only need the tags pushed early to build the Windows wheels via git push --tags. The Linux and macOS wheels are built using their own dedicated wheel builder. The git push --all just delays the CI from building all these wheels.

So git push --all which pushes main and 9.5.x can come after all the wheel building.

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Next, during the "Binary Distributions" stage, it says to download the Windows wheels (once they're ready); then do some things to kick off the macOS and Linux wheel builder and download once ready.

Let's flip the order. Even if Windows wheels were ready (and they won't be yet), it's better to get the Mac/Linux CI queued up first.

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Finally, I used the GitHub CLI gh to download all the wheels before uploading them. Saves a lot of clicking in the UI! So let's include example commands for next time.

(Aside: gh co 1234 is a really handy command for checking out a PR for local testing.)

[radarhere]

I gather you were thinking that this command would be run from the main repository, so that all of the files would be in one neat 'dist' directory.

However, in the previous point, the user cloned and navigated into pillow-wheels. So I feel like this is confusing. It would be good to either clarify that this should be run from the main repository, or if this is run from pillow-wheels, then --repo python-pillow/pillow-wheels is unnecessary.

[hugovk]

That's right, I ran both these commands from the main repo, and agree this is confusing. Will clarify!

[hugovk]

Added cb68187 (and rebased in the PyQt workaround).