Removes `testenv` annotations and related code. These annotations originally let you skip x-pack snippet tests in the docs. However, that's no longer possible.
Relates to #79309, #31619
* Put Shutdown API docs
* Get Shutdown API docs
* Properly escape regex
* Doc tests build now! (but don't pass)
* Doc tests pass now! (with a code fix that will go in a different PR)
* DELETE shutdown docs
* Edit for language & consistency
* Fix doctest
* Add cloud-only banner
* Add allocation_delay docs
* Restore file that got deleted somehow?
* Use `restart` type in example to demonstrate `allocation_delay` param
* Fix typo per review
Co-authored-by: debadair <debadair@elastic.co>
* Vastly improve wording per review
Co-authored-by: debadair <debadair@elastic.co>
* Adjust test request & response so it passes
Co-authored-by: Deb Adair <debadair@elastic.co>
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
