Update PolicyException charts to new apiVersion

In new Kyverno v1.12.5 the apiVersion has been updated:

$ kubectl explain PolicyException.apiVersion

GROUP:      kyverno.io
KIND:       PolicyException
VERSION:    v2

Need to update and test these charts to new version:

chart/templates/exception-require-non-root-group.yaml:apiVersion: kyverno.io/v2beta1
chart/templates/exception-require-non-root-user.yaml:apiVersion: kyverno.io/v2beta1
chart/templates/update-automountserviceaccounttokens.yaml:apiVersion: kyverno.io/v2beta1