feat: prefer Config over FlatConfig when they're equal (#674)

Co-authored-by: JounQin <[email protected]>

Author: irsooti

.changeset/lucky-badgers-judge.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-prettier": minor
+---
+
+feat(types): prefer `Config` over `FlatConfig` when they're equal

recommended.d.ts

@@ -1,5 +1,12 @@
 import { Linter } from 'eslint';
 
-declare const recommendedConfig: Linter.FlatConfig;
+// prettier-ignore
+type IfEqual<A, B, X = A, Y = B> =
+  (<G>() => G extends A & G | G ? 1 : 2) extends
+  (<G>() => G extends B & G | G ? 1 : 2)
+    ? X
+    : Y;
+
+declare const recommendedConfig: IfEqual<Linter.Config, Linter.FlatConfig>;
 
 export = recommendedConfig;