https://docs.moodle.org/dev/Releases has been moved to https://moodledev.io/general/releases

It seems like some Moodle pages including /admin/index.php need to be updated, see https://github.com/moodle/moodle/blob/12a81769265a4fa75232ff1639423be1565c9fa9/admin/renderer.php#L993 and https://github.com/moodle/moodle/blob/12a81769265a4fa75232ff1639423be1565c9fa9/admin/renderer.php#L748

PS: If there is an existing tracker for this please feel free to make a link and close this off.