also relax in swift-6.2 package swift, which gets picked up by newer versions

Author: diederich

Package@swift-6.2.swift

@@ -48,7 +48,7 @@ let package = Package(
     ],
     traits: [tracingTrait],
     dependencies: [
-        .package(url: "https://github.com/swiftlang/swift-syntax", "600.0.0"..<"603.0.0")
+        .package(url: "https://github.com/swiftlang/swift-syntax", "600.0.0"..<"604.0.0")
     ],
     targets: [
         .target(