libdecor: 0.1.0 -> 0.1.1, remove unused dependency

[Kiskae]

Description of changes

Prompted by #227457 when investigating why libdecor depends on the nvidia egl platform.

• Updated project home per notice on the old repository
• Update to 0.1.1
• Turns out egl should be provided by libGL, but since it is only required by the unused demo application I just disabled it and removed the dependency.

@Artturin I noticed that there is an libdecor-gtk.so plugin that isn't currently being built. I didn't add a gtk3 dependency since I'm not sure what the purpose of those plugins is but you might want to have a look.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[Kiskae]

It looks like the libdecor-gtk plugin was added after the 0.1.1 release, my bad