update chart to version 12.10.0
Most of the images for kube-prometheus-stack version 12.10.0 are available in the IronBank. Only images missing are version 0.44.0 of prometheus-operator and prometheus-config-reloader.
Once those images are released, we can update the chart version which will use the following new images: grafana:7.3.1 alertmanager:v0.21.0 prometheus:v2.22.1