Checkout PRConfig by default in *head slots
PRConfig contains the TestFileDB, which is expected to change occasionally when we work on tests. This should not need a release in order to be picked up the nightlies. See LBCORE-1524
PRConfig contains the TestFileDB, which is expected to change occasionally when we work on tests. This should not need a release in order to be picked up the nightlies. See LBCORE-1524