Create Rancher 2.14-head (new Rancher head) lane and Update PR lane to point to 2.13

[sbulage]

After release of Rancher 2.13.0, we have to change our CI pointing to head again (2.14-head).
Also, we have to change Rancher version used in PR CI lane too,

Below table illustrates what will be going to change in CI.

head CI Change	Current	Updated to
	UI-RM_head --> 2.13-head	UI-RM_head --> 2.14-head
	UI-RM_head	UI-RM_head_2.13 (separate job)

PR CI Change	Current	Updated to
	2.11	2.13