kube-prometheus: Remove unnecessary namespace selectors

jsonnet/kube-prometheus/alertmanager/alertmanager.libsonnet

...rometheus/kube-state-metrics/kube-state-metrics.libsonnet

...net/kube-prometheus/node-exporter/node-exporter.libsonnet

...metheus/prometheus-operator/prometheus-operator.libsonnet

jsonnet/kube-prometheus/prometheus/prometheus.libsonnet

manifests/0prometheus-operator-serviceMonitor.yaml

manifests/alertmanager-serviceMonitor.yaml

manifests/kube-state-metrics-serviceMonitor.yaml

manifests/node-exporter-serviceMonitor.yaml

manifests/prometheus-serviceMonitor.yaml