run-make: work around package conflicts from llvm.sh

run-make: work around package conflicts from llvm.sh

packages installed by llvm.sh sometimes conflict with existing packages
from earlier versions, leading to errors like:

> The following packages have unmet dependencies:
> python3-lldb-13 : Conflicts: python3-lldb-x.y
> python3-lldb-19 : Conflicts: python3-lldb-x.y

remove packages from any earlier versions before running llvm.sh

Fixes: https://tracker.ceph.com/issues/70792
Signed-off-by: Casey Bodley <cbodley@redhat.com>
(cherry picked from commit 54f0fe19447308f2127ad4bacecfa0aab4e44c4d)