mgr/dashboard: access_control: add grafana scope read access t… (#29989)

mgr/dashboard: access_control: add grafana scope read access to *-manager roles

Reviewed-by: Lenz Grimmer <LGrimmer@suse.com>
Reviewed-by: Volker Theile <vtheile@suse.com>
Reviewed-by: Ernesto Puerta <epuertat@redhat.com>

diff --cc src/pybind/mgr/dashboard/services/access_control.py
Simple merge