The PSPs have long since been deprected. In K8s 1.21 the PSPs
were first deprecated, and support was completely removed
for them in 1.25. With Rook v1.11, the min supported version of
K8s is now 1.21. To reduce confusion in the documentation,
mention of the PSPs is now removed from the 1.11 docs.
For the corner case that users still require the PSPs,
the helm chart still contains the option for creating PSPs
or other users can still create the psp.yaml.
Signed-off-by: Travis Nielsen <tnielsen@redhat.com>