Change swift-syntax version from exact to from

Author: Mx-Iris

Package.swift

@@ -15,7 +15,7 @@ let package = Package(
     dependencies: [
         .package(
             url: "https://github.com/apple/swift-syntax.git",
-            exact: "509.0.0"
+            from: "509.0.0"
         ),
         .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.3.0"),
         .package(url: "https://github.com/SwiftPackageIndex/SPIManifest.git", from: "0.12.0"),