Use arguments instead of argumentList in the macro template (#7422)

`argumentList` has been deprecated. We should use `arguments` instead.

Sources/Workspace/InitPackage.swift

@@ -836,7 +836,7 @@ public final class InitPackage {
  of node: some FreestandingMacroExpansionSyntax,
  in context: some MacroExpansionContext
  ) -> ExprSyntax {
- guard let argument = node.argumentList.first?.expression else {
+ guard let argument = node.arguments.first?.expression else {
  fatalError("compiler bug: the macro does not have any arguments")
  }