RHEL/Rocky 9 documentation

[donsizemore]

What this PR does / why we need it:

Update installation documentation for RHEL/Rocky 9

Which issue(s) this PR closes:

Closes #8856

Special notes for your reviewer:

None

Suggestions on how to test this:

Perform installation on RHEL/Rocky 9

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

No

Is there a release notes update needed for this change?:

No

Additional documentation:

None