Add one more 1.12 changelog item (#17936)

Author: JukkaL

CHANGELOG.md

@@ -255,6 +255,7 @@ This feature was contributed by Ivan Levkivskyi (PR [17457](https://github.com/p
  * Improvements to `functools.partial` of types (Shantanu, PR [17898](https://github.com/python/mypy/pull/17898))
  * Make ReadOnly TypedDict items covariant (Jukka Lehtosalo, PR [17904](https://github.com/python/mypy/pull/17904))
  * Fix union callees with `functools.partial` (Jukka Lehtosalo, PR [17903](https://github.com/python/mypy/pull/17903))
+ * Improve handling of generic functions with `functools.partial` (Ivan Levkivskyi, PR [17925](https://github.com/python/mypy/pull/17925))
 
 ### Typeshed Updates