appveyor のimageを Visual Studio 2022 の imageに更新してエラーを修正する

https://ci.appveyor.com/project/sakuraeditor/changelog-sakura/builds/45282299

ERROR:  Error installing github_changelog_generator:
    The last version of activesupport (>= 0) to support your Ruby & RubyGems was 6.1.7. Try installing it with `gem install activesupport -v 6.1.7` and then running the current command again
    activesupport requires Ruby version >= 2.7.0. The current ruby version is 2.5.5.[15]

https://ci.appveyor.com/project/sakuraeditor/changelog-sakura/builds/41905621 までは成功しているが https://ci.appveyor.com/project/sakuraeditor/changelog-sakura/builds/41920497 から失敗している。

sakura-editor / changelog-sakura

appveyor のimageを Visual Studio 2022 の imageに更新してエラーを修正する #33