The `kube` page index gets a weight of 300 and its child pages should
get weight values starting > 300.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

Signed-off-by: Michael Friedrich <mfriedrich@gitlab.com>

Signed-off-by: Saswata Mukherjee <saswataminsta@yahoo.com>

Changed in https://github.com/prometheus-operator/kube-prometheus/commit/42a3ac0606818541e66a111693d3ff98c642f7a8 from `kube-prometheus` to `main`

replaced default namespaces rbac rules by a loop


set right variable name