pantheon.appcenter: 3.7.1 -> 3.8.0

[bobby285271]

Motivation for this change

Part of Pantheon 6.0.2 updates (previous one at #130380).

The homepage flag was dropped. however both the bannner and the recently-updated apps is not showing correctly on NixOS, I reverted the change for now.

https://github.com/elementary/appcenter/releases/tag/3.8.0
elementary/appcenter@3.7.1...3.8.0

New features:

• Show content warnings on app info pages

Fixes:

• Show other apps by an author for Flatpak sources
• Populate banner on home locally instead of relying on an external API

Improvements:

• Greatly increased number of recently-updated apps shown on home page
• Navigate banners on the home page with multitouch gestures
• Updated translations

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.

[davidak]

Change looks good

Builds, works

[davidak]