curl: add patch for CVE-2021-22945

[risicle]

Motivation for this change

https://curl.se/docs/CVE-2021-22945.html

Included patch as all curl patches need to be in-repo due to bootstrapping issues.

Patching instead of bumping because we're still stuck in a log jam over curl (#124502).

(Only built the anonymous early-stage curl on darwin as the bootstrap loop is so big)

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 via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all packages 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/)
• 21.11 Release Notes (or backporting 21.05 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.

[vcunat]

I'd really prefer if we could unblock updates in some of the proposed ways.

[lukegb]

I'm keen to land any sort of patch for this, but I agree that this can't be the direction going forwards.