Add new non scalar: `taken_by`

[rtanglao]

• See log file: github-action-thunderbird-aaq/actions/runs/23156524910/job/67272681217 which is from question 1571147
• Add support for taken_by to https://github.com/thunderbird/github-action-thunderbird-aaq/blob/main/get-tb-creator-answers-questions-for-arbitrary-time-period.rb

E, [2026-03-16T17:16:51.724381 #2269] ERROR -- : unknown non scalar: key:taken_by value:{
        "username" => "Mapenzi",
    "display_name" => "Mapenzi",
          "avatar" => "https://firefoxusercontent.com/cf1dc1320d8b99b945b166bd83018b0b"
}