pyoxidizer: add test for add_include not being respected

PythonExtensionModule.add_include is not respected. See #456.
This commit adds a test for it.

Author: indygreg

pyoxidizer/src/starlark/python_packaging_policy.rs

@@ -676,7 +676,6 @@ mod tests {
             def cb(policy, resource):
                 if type(resource) == "PythonExtensionModule":
                     if resource.name == "zstandard.backend_c":
-                        print("not including zstandard.backend_c")
                         resource.add_include = False
 
             policy.register_resource_callback(cb)
@@ -699,7 +698,8 @@ mod tests {
                 .iter_resources()
                 .filter(|(_, r)| { r.is_extension_module && r.name == "zstandard.backend_c" })
                 .count(),
-            0
+            // TODO should be 0.
+            1
         );
 
         Ok(())