Added rhel gha workflow

[eklee15]

Description of Change

Added GHA workflow for RHEL 9.6.
This workflow was tested in my private repo using a self-hosted runner (rhel-ek-cloud)

1. Needed to build the Slurm from scratch (instead of dnf install) because dnf install slurm only provides outdated version (22.x).
2. 22.x version created building problem list_t not found in slurm.h
3. This test would approximately take ~20 mins
4. There are things to adjust to reduce testing time (rpmbuild -ta) by excluding unused sub-packages
5. I will need permission to create a self-hosted runner on this repo.
6. The test completion snapshot is as follows:

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