Documentation Update
Update section Pre-configured Sites section:

• hercules / orion
  • describe required manual changes to stack-oneapi and stack-intel-oneapi-mpi module files
  • see: Orion & Hercules module config issue for spack-stack-1.9.0
• add entry for ursa
• note that support for jet ends June 2025

Additional context
Updates for spack-stack release/1.9.1