[python] don't generate args default expressions

in functions declarations (fixes #8542)

src/generators/genpy.ml

@@ -1145,7 +1145,7 @@ module Printer = struct
 						| None -> ""
 						| Some ct ->
 							had_value := true;
-							Printf.sprintf " = %s" (print_expr pctx ct)
+							" = None"
 		) args in
 		String.concat "," sl
 

tests/misc/python/projects/Issue8542/Main.hx

@@ -0,0 +1,9 @@
+class Main {
+	public function new(e:E = E.Ea) {}
+
+	public static function main(){}
+}
+
+enum E {
+	Ea;
+}

tests/misc/python/projects/Issue8542/build.hxml

@@ -0,0 +1,3 @@
+-python bin/test.py
+--main Main
+-cmd python3 bin/test.py