Convert Github Action workflows to build dependencies with Spack

[kgerheiser]

DESCRIPTION OF CHANGES:

Use Spack to build dependencies in Github Actions workflows. A new file ci/spack.yaml controls the libraries and versions that are built. This follows UPP, GSI, and WW3 which have recently converted to Spack in their CI.

The build/testing is split into two steps:

1. A setup step that build the dependencies with Spack per compiler/OS (GCC/Intel) which are then cached for the next step.
2. A build/test phase which load the cached dependencies and then builds/tests UFS_UTILS.

A debug/release/doc build still needs to be added.

TESTS CONDUCTED:

Unit tests pass in Github Actions.

ISSUE:

FIx #668