Fix Jemalloc Dependency Issue

Currently we insert the shared object file libjemalloc.so.2 in /var/lib/columnstore. This was a work around due to the fact that jemalloc was only included in the epel-release repo for RedHat derivatives (CentOS, Fedora). A customer without external internet access may not have had a way to connect with this "extra packages" repo.

dbart has agreed to begin syncing this RPM package from epel-release into the official MariaDB Community and Enterprise repos. This will allow us to call this RPM as a dependency for MariaDB-columnstore-engine and have the shared object available in the correct default location /usr/lib64

In fact, this looks to already be in place for community: https://downloads.mariadb.com/MariaDB/mariadb-10.5.9/yum/centos/7/x86_64/rpms/

This is going to require a change to the MariaDB-columnstore-engine RPM package as well as a possible change to the path in which Columnstore looks for jemalloc.