MDEV-14881 cmake should succeed after installing libaio.

In case libaio is not found, and required,
remove variables HAVE_LIBAIO_H and HAVE_LIBAIO from cache, so that cmake
rerun after installation of libaio would succeed.

cmake/build_configurations/mysql_release.cmake

@@ -128,6 +128,8 @@ IF(UNIX)
       CHECK_INCLUDE_FILES(libaio.h HAVE_LIBAIO_H)
       CHECK_LIBRARY_EXISTS(aio io_queue_init "" HAVE_LIBAIO)
       IF(NOT HAVE_LIBAIO_H OR NOT HAVE_LIBAIO)
+        UNSET(HAVE_LIBAIO_H CACHE)
+        UNSET(HAVE_LIBAIO CACHE)
         MESSAGE(FATAL_ERROR "
         aio is required on Linux, you need to install the required library: