update setup to run spack compiler find

Signed-off-by: Gregory Becker <becker33@llnl.gov>

Author: becker33

common/setup.rst

@@ -11,6 +11,7 @@
        spack repo update builtin --tag v2025.07.0
        spack mirror add tutorial /mirror
        spack buildcache keys --install --trust
+       spack compiler find
 
    See the :ref:`basics-tutorial` for full details on setup. For more help, join us in the ``#tutorial`` channel on Slack -- get an invitation at `slack.spack.io <https://slack.spack.io/>`_