Update DiagnosticsFormatter.swift

Use correct fileheader

Author: flashspys

Sources/swift-parser-test/DiagnosticsFormatter.swift

@@ -1,9 +1,15 @@
+//===------------ DiagnosticsFormatter.swift - Formatter for diagnostics ----------===//
 //
-//  File.swift
-//  
+// This source file is part of the Swift.org open source project
 //
-//  Created by Felix Wehnert on 02.10.22.
+// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
 //
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
 
 import Foundation
 import SwiftParser