chore: allow for swift-syntax of 603.0.0

Author: Brett-Best

Package.swift

@@ -21,7 +21,7 @@ let package = Package(
     dependencies: [
         .package(url: "https://github.com/apple/swift-async-algorithms.git", from: "1.0.0"),
         .package(url: "https://github.com/nicklockwood/SwiftFormat.git", from: "0.54.1"),
-        .package(url: "https://github.com/swiftlang/swift-syntax.git", "600.0.0" ..< "603.0.0"),
+        .package(url: "https://github.com/swiftlang/swift-syntax.git", "600.0.0" ..< "604.0.0"),
     ],
 
     targets: [

Sources/VexilMacros/FlagContainerMacro.swift

@@ -23,6 +23,7 @@ extension FlagContainerMacro: MemberMacro {
     public static func expansion(
         of node: AttributeSyntax,
         providingMembersOf declaration: some DeclGroupSyntax,
+        conformingTo protocols: [TypeSyntax],
         in context: some MacroExpansionContext
     ) throws -> [DeclSyntax] {
         // If the declaration doesn't have any scopes attached we might be inheriting scopes from a public extension