configib: fix/clean up el9 support

[alexrichert]

The PR is to fix issue #7453

The modifications include

• Remove EL9-specific logic from non-redhat OSes
• Add EL9 connections with nmcli before modifying them for nicextraparams
• Don't populate $cfgfile when using EL9

The UT result

##The UT output##

[alexrichert]

@Obihoernchen I noticed a number of issues with my previous attempt, 🤞 this should work better...

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[alexrichert]

We've tested with EL8 and EL9. It doesn't break EL8, and in EL9, it creates a NM connection and does not try to remove or write an ifcfg file.