Add note about SUSE and Photon OS

[ScriptAutomate]

• The previous Salt Install Guide, prior to migrations, directed users to make use of the SUSE-provide packages of Salt. This restores that, along with an included note about Photon OS
• Though our onedir (relenv) packages are tested in CI/CD on Photon OS and openSUSE, Salt Project will not be providing directions for additional package managers outside of dnf for RPM-based installs
  • In the meantime, there is a related issue opened for expanding tdnf to support glob lists in excludepkgs (and potentially exclude as an alias to excludepkgs): tdnf 3.5.2 does not respect excludepkgs with globbing on a custom repo vmware/tdnf#505
• This PR also supersedes add linux-rpm install for zypper #14