Network connection still breaks the nightly

[jcfreeman2]

In a nutshell, last night's v5 nightly (https://github.com/DUNE-DAQ/daq-release/actions/runs/13106231767) failed due to the error

==> Error: FetchError: All fetchers failed for spack-stage-dpdklibs-NFD_DEV_250203_A9-hf3xhxual3zx62e2l47exnkos5jntflx

It appears that this resulted in a non-retryable error code.

[jcfreeman2]

Andrew handled this with the following commits:

commit 5de824f30e9db69b714a00cff834a2609141ef08
Author: Andrew Mogan <amogan@fnal.gov>
Date:   Mon Feb 3 11:06:21 2025 -0600

    Improve spack install exit code logging

commit 9ef4aaf2b86cb577ae73d8379248678de7f72cf5
Author: Andrew Mogan <amogan@fnal.gov>
Date:   Mon Feb 3 10:59:25 2025 -0600

    Redict both stdout and stderr from spack install
    
    A recent nightly failed due to a connection error that wasn't caught
    correctly. I believe this was because the spack FetchError wasn't
    written to dunedaq_build_spack_install.log since it wasn't part of
    stdout. Adding a 2>&1 will hopefully solve this.