Update postgresql

[trevor-vaughan]

Posgresql 9.6 has been archived and is no longer supported.

[trevor-vaughan]

The latest puppetdb requires PostgreSQL 11 or later. EL8 ships 10 as the default and it should actually work fine.

Going to attempt to pull it from the DNF modules instead of downloading directly from the PG site and see what happens.

[trevor-vaughan]

AppStream for EL8 has all of the postgres versions except 11 and the puppetdb module seems to pin to either 9.6 or 11 by default.

Experimenting to see if the default module set works with anything later without having to prod a bunch of variables. The puppetdb module uses the params method which creates a hot mess of trying to override anything.

[trevor-vaughan]

Work for this got mixed into #861.

Need folks to decide if they want to go that way or back out the postgres repo changes.

So far, it looks like using the Streams version will work, but it needs more extensive testing.

[op-ct]

6.6.0 backed out of postgres repo changes, now that 6.6.0 is released new work should incorporate them.

This will inevitably lead into updating our puppetdb module, in which case #843 will probably become relevant.

[michael-riddle]

This is causing issues when shipping the new ISOs because puppetdb is requiring postgresql 11 by default with the latest version.