latest final release of Unicode is 10.0.0. 11.0.0 is not yet released.

Motivation for this change

see #29891 (review)

I think it is better not to depend on not-yet-released Unicode data. I guess this file will be renamed UnicodeData.txt in the future, and this URL will break.
— @xzfc

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
  • Linux
• 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.