[Woptim] RADIUSS Spack Configs update

[adrienbernede]

Supersedes #517 (Update Shared CI, add poodle, update Spack configs accordingly.)

Adds Update to 2023-12-0 release of Shared CI, with fix of flux allocations to allow MPI tests, and improvement of reproducer. Update to 2023-12-3 release of Shared CI, with fixed reproducer. Update the submodule RADIUSS Spack Configs

Purpose

In RADIUSS Spack Configs:

• The compilers (wrappers) on Lassen have been updated to better support the use of gcc 8.3.1 toolchain.
• The local spack packages have been updated to be as close as possible to what we are pushing in https://github.com/spack/spack/pull/41375.

Notes

Packages in RADIUSS Spack Configs still have some specific changes compared to the PR mentioned above.

Supersedes #520