Replace "|&" syntax with "2>& |" syntax

[christopherwharrop-noaa]

Summary

Fixes #973. Older versions of bash (< 4.1?) do not recognize the |& syntax for some reason. So this PR replaces the use of |& with the more verbose, but equivalent, 2>&1 | syntax.

Testing

Sourcing of ./setup.sh was tested on Mac laptop having old version of bash ( 3.2.57) and on Hercules having a newer version of bash (5.1.8).

Applications affected

Impacts only the installation of spack-stack

Systems affected

Impacts anyone installing spack-stack on a system with an old version of bash that doesn't support the |& syntax.

Dependencies

N/A

Issue(s) addressed

Fixes #973

Checklist

• This PR addresses one issue/problem/enhancement, or has a very good reason for not doing so.
• These changes have been tested on the affected systems and applications.
• All dependency PRs/issues have been resolved and this PR can be merged.

[climbfuji]

Thanks! I prefer 2>&1 | anyway ;-)

Keep using your old Big Sur system so that we find all these little bugs!