[TECH DEBT] Remove support for RHEL 5

[dmurphy18]

Description of the tech debt to be addressed, include links and screenshots

In salt/modules/yumpkg.py there is code for checking functionality of RHEL 5

salt/salt/modules/yumpkg.py

Lines 264 to 265 in 51f19f1

	if int(grains.get("osmajorrelease")) == 5
	else "yum-plugin-versionlock"

Need to go through code and remove similar, RHEL 5 and 6 are long since EOL

Versions Report

Found during triage, during Salt 3005 release.