fonts.fontconfig-penultimate: remove dependency on fontconfig_210

[NickHu]

Motivation for this change

Since #93562 was merged,
configurations which set fonts.fontconfig.penultimate.enable to true
will fail to build, tripping the assertion:

fontconfig 2.10.x hasn't had a release in years, is vulnerable to CVE-2016-5384
and has only been used for old fontconfig caches.

This rectifies the module, deleting references to fontconfig_210. I just
did the most obvious thing possible to make it build, and didn't really
think properly about the consequences, so I would appreciate some review
on this one from someone who knows the fontconfig stuff a bit better.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• 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 nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[flokli]

I wonder if we should keep penultimate at all: #92571 (comment)

[flokli]

I opened #95681 removing fontconfig-pentultimate.

[NickHu]

Ah, I didn't realise that upstream fontconfig-penultimate hasn't been updated in over 3 years. I guess what you propose makes more sense.