#12716 removed the mem limit for single load task, in this PR I propose to remove the session variable load_mem_limit, to avoid confusing. For compatibility, load_mem_limit in thrift not removed, the value is set equal to exec_mem_limit in FE
#12716 removed the mem limit for single load task, in this PR I propose to remove the session variable load_mem_limit, to avoid confusing. For compatibility, load_mem_limit in thrift not removed, the value is set equal to exec_mem_limit in FE