Merge release note entry for Date/Time/DateTime extensions

The first release note entry mentioned #on_weekday?, but that was only
added by the second PR mentioned there. To simplify reading the notes
just merge the two, since they are related methods. [ci skip]

Author: carlosantoniodasilva

guides/source/5_0_release_notes.md

@@ -1000,7 +1000,8 @@ Please refer to the [Changelog][active-support] for detailed changes.
 
 *   Added `#on_weekend?`, `#on_weekday?`, `#next_weekday`, `#prev_weekday` methods to `Date`,
     `Time`, and `DateTime`.
-    ([Pull Request](https://github.com/rails/rails/pull/18335))
+    ([Pull Request](https://github.com/rails/rails/pull/18335),
+     [Pull Request](https://github.com/rails/rails/pull/23687))
 
 *   Added `same_time` option to `#next_week` and `#prev_week` for `Date`, `Time`,
     and `DateTime`.
@@ -1051,9 +1052,6 @@ Please refer to the [Changelog][active-support] for detailed changes.
 *   Added `Array#second_to_last` and `Array#third_to_last` methods.
     ([Pull Request](https://github.com/rails/rails/pull/23583))
 
-*   Added `#on_weekday?` method to `Date`, `Time`, and `DateTime`.
-    ([Pull Request](https://github.com/rails/rails/pull/23687))
-
 *   Publish `ActiveSupport::Executor` and `ActiveSupport::Reloader` APIs to allow
     components and libraries to manage, and participate in, the execution of
     application code, and the application reloading process.