eslint-config-prettierのバージョン8.0.0 (2021-02-21) で
All configs have been merged into one!
という事らしいです。
具体的には
{ "extends": [ "some-other-config-you-use", "prettier", "prettier/@typescript-eslint", "prettier/babel", "prettier/flowtype", "prettier/react", "prettier/standard", "prettier/unicorn", "prettier/vue" ] }
みたいに書いてたとこが、
{ "extends": [ "some-other-config-you-use", "prettier" ] }
とだいぶスッキリに