don't require jemalloc for 10.5 official packages

it was only for TokuDB, and TokuDB isn't packaged in 10.5

cmake/build_configurations/mysql_release.cmake

@@ -98,7 +98,6 @@ ELSEIF(RPM)
   SET(WITH_ZLIB system CACHE STRING "")
   SET(CHECKMODULE /usr/bin/checkmodule CACHE FILEPATH "")
   SET(SEMODULE_PACKAGE /usr/bin/semodule_package CACHE FILEPATH "")
-  SET(WITH_JEMALLOC "yes" CACHE STRING "")
   SET(PLUGIN_AUTH_SOCKET YES CACHE STRING "")
   SET(WITH_EMBEDDED_SERVER ON CACHE BOOL "")
   # not yet, SLES 12.3 doesn't provide pcre2
@@ -108,7 +107,6 @@ ELSEIF(DEB)
   SET(WITH_ZLIB system CACHE STRING "")
   SET(WITH_LIBWRAP ON)
   SET(HAVE_EMBEDDED_PRIVILEGE_CONTROL ON)
-  SET(WITH_JEMALLOC "yes" CACHE STRING "")
   SET(PLUGIN_AUTH_SOCKET YES CACHE STRING "")
   SET(WITH_EMBEDDED_SERVER ON CACHE BOOL "")
   SET(WITH_PCRE system CACHE STRING "")