puppet: refactor remove puppetdb_major_version

puppetdb_major_version: 4 is now the default and so this variable is no longer
required

The following values are still required as the puppet masters and db's
are still running puppet4/facter2. Theses variables will get removed
once all servers have been upgraded

• profile::base::puppet::facter_major_version
• profile::base::puppet::puppet_major_version:

Hosts: re:^(puppet(db|master)|rhodium).*\.wmnet$

Bug: T227587
Change-Id: I14fe82a198b142d140683328660d7ae39589d703