Merge branch 'docs/k8s-proxy-scope' into 'master'

Document `k8s_proxy` scope for PATs, PrATs and GATs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131774



Merged-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Hunter Stewart <hustewart@gitlab.com>
Reviewed-by: Phillip Wells <pwells@gitlab.com>
Co-authored-by: Timo Furrer <tfurrer@gitlab.com>