Summary

1. Add a new tier 1 site config for Blueback. Blueback is very similar to Narwhal, i.e. a Cray system but with a slightly newer software environment. The same features and limitations as for Narwhal apply: We still need to use the Cray compiler wrappers for the regular environments (unified environment, NEPTUNE standalone environment), but we need to use the GCC compilers without the Cray wrappers for the Cylc environment.
2. On Narwhal, bump gcc from 10.3.0 to 12.2.0 to fix compilation errors with the latest met/metplus. Also, fix the long-standing problem with applications being linked against multiple cray-libsci versions by adding an extra_rpaths entry in the compiler config (credits to the NavyDSRC and HPE teams).
3. Minor updates and consistency changes for other NRL site configs Atlantis, Cole, Tusk.

Testing

Installed the following environments with the supported compilers on each platform on all NRL sites (Atlantis, Blueback, Cole, Narwhal, Nautilus, Tusk):

• unified environment
• NEPTUNE standalone environment
• cylc environment

Applications affected

All applications running on these systems.

Systems affected

Atlantis, Blueback, Cole, Narwhal, Nautilus, Tusk

Dependencies

n/a

Issue(s) addressed

Working towards #1116

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.