[gnome-software] (6 commits) ...Merge branch '603-gnome-software-reports-unknown-error-when-there-is-a-signing-issue' into 'main'

[Philip Withnall <pwithnall src gnome org>]

Summary of changes:

  3e0db32... packagekit: Recognize when the user declined an operation (*)
  07b1a5f... gs-plugin: Add 'ask-untrusted' signal (*)
  c6d1f5d... gs-common: Add gs_utils_ask_user_accepts() (*)
  719b009... gs-shell: Add a handler for the GsPluginLoader::ask-untrust (*)
  6e6175f... packagekit: Ask the user what to do when there's a package  (*)
  9df2647... Merge branch '603-gnome-software-reports-unknown-error-when

(*) This commit already existed in another branch; no separate mail sent