Increase swift-tools-version to 5.7

ahoppen · ahoppen · commit 83a1f2d81ea0 · 2023-05-01T19:55:50.000-07:00
We no longer need to support building SwiftSyntax with Swift &lt;5.7 so we can increase the tools version.

rdar://108753223
diff --git a/Package.swift b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.5
+// swift-tools-version:5.7
 
 import PackageDescription
 import Foundation
