Use encoded string since `ModuleNode.full_module_name` may originate from different sources.

See https://github.com/cython/cython/pull/4764

Cython/Compiler/ModuleNode.py

@@ -2633,7 +2633,7 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             code.putln(code.error_goto_if_neg(
                 '__Pyx_SetPackagePathFromImportLib(%s)' % (
                     code.globalstate.get_py_string_const(
-                        self.full_module_name).cname),
+                        EncodedString(self.full_module_name)).cname),
                 self.pos))
             code.putln("}")