fix format gaffe

Author: morganchen12

FirebaseAI/Sources/PartsRepresentable.swift

@@ -29,7 +29,8 @@ public extension Part {
 
 /// Enable an `Array` of ``PartsRepresentable`` values to be passed in as a single
 /// ``PartsRepresentable``.
-extension [PartsRepresentable]: PartsRepresentable {
+// swiftformat:disable:next typeSugar
+extension Array<PartsRepresentable>: PartsRepresentable {
   // Note: this is written as Array<T> instead of [T] because
   // devsite doesn't like it when a toc title begins with [].
   public var partsValue: [any Part] {