Add deprecation logging when _all is enabled (#26228)

* Add deprecation logging when _all is enabled

In 6.0 `_all` is not configurable and disabled by default.

Relates to #22144

* Log deprecation regardless of whether _all is enabled or disabled

* Add expected warnings in REST tests

* Assert warnings in unit tests

* Add warning check to various documentation tests

* Add assertWarnings if randomBoolean() is true for enabled