Fix “Unsafe usage of new static()” by making EmptyResponse final

[arshidkv12]

Marking EmptyResponse as final prevents late static binding issues
when instantiating with new static(), ensuring type safety and
avoiding potential runtime errors in subclasses.

Q	A
Documentation	no
Bugfix	yes
BC Break	yes
New Feature	no
RFC	no
QA	no

Description

Marking EmptyResponse as final prevents late static binding issues
when instantiating with new static(), ensuring type safety and
avoiding potential runtime errors in subclasses.

[samsonasik]

This is bc break, can't land in minor version.

There should be no child for this class, extends parent Response instead.

If needed, use

/** @final */

so no bc break, while inform user to not extends it.