avahi: add patch for CVE-2021-3468

[yorickvP]

Description of changes

Ubuntu and debian are shipping this: https://ubuntu.com/security/CVE-2021-3468
Redhat is not. The patch has not been accepted upstream. (2022-10-10)

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/)
• 22.11 Release Notes (or backporting 22.05 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
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[github-actions]

Backport failed for staging-22.05, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git fetch origin staging-22.05
git worktree add -d .worktree/backport-195331-to-staging-22.05 origin/staging-22.05
cd .worktree/backport-195331-to-staging-22.05
git checkout -b backport-195331-to-staging-22.05
ancref=$(git merge-base 579766d1fda7fc2a52db4ed822f08bdbf3440cb5 039e1a05f5db32f5e9ff9dfe13501d631b7001bf)
git cherry-pick -x $ancref..039e1a05f5db32f5e9ff9dfe13501d631b7001bf

[github-actions]

Backport failed for staging-22.05, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git fetch origin staging-22.05
git worktree add -d .worktree/backport-195331-to-staging-22.05 origin/staging-22.05
cd .worktree/backport-195331-to-staging-22.05
git checkout -b backport-195331-to-staging-22.05
ancref=$(git merge-base 579766d1fda7fc2a52db4ed822f08bdbf3440cb5 039e1a05f5db32f5e9ff9dfe13501d631b7001bf)
git cherry-pick -x $ancref..039e1a05f5db32f5e9ff9dfe13501d631b7001bf

[risicle]

In future please set the patch's name to e.g. CVE-2021-3468.patch. Some vulnerability-scanning tools are able to detect these to avoid spurious warnings.