Motivation for this change

A simple version bump; main was updated to 1.23 in 0be3f2c, it doesn't make sense to keep 1.23.0-beta0 around, does it?

/cc @NeQuissimus

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

Note: I have no idea what I'm doing. Seriously. I was just mimicking 0be3f2c. I think hash at least is correct (computed via nix-hash --base32 --type sha256 --flat). I hope I'm not just needlessly wasting anyone's time.