Bump version to 0.0.1-alpha.23

[sharkdp]

I excluded the following items from the CHANGELOG. Let me know if you want one of these to be included:

• Rooster config: ignore PRs labelled documentation or playground when generating the changelog (#1360)
• refactor Place (#20871)
• Standardize syntax error construction (#20903)
• Use field-specifier return type as the default type for the field (#20915)
• Do not bind self to non-positional parameters (#20850)

The last one is in principle observable, but sounds much more scary than it is, as it only affected CallableTypeOf[…], I believe.

[AlexWaygood]

Remove "pre-release software" warning (#20817)

That one has actually been asked for by users, I think (#1253) so it might be worth including!

Rooster config: ignore PRs labelled documentation or playground when generating the changelog (#1360)

Hah. We should probably also ignore PRs labelled release so this kind of thing is auto-excluded 😆

cache Type::is_redundant_with (#20477)

This was a big performance improvement and fixed hangs on some projects! Definitely worth including, I think

[AlexWaygood]

Thank you!