Jsonnet dashboards job selectors are not aligned with monitoring resources

#### Describe the bug
Jsonnet dashboards `job` selectors are not aligned with monitoring resources.
`job` selectors in panels use `PodMonitor` [syntax](https://github.com/grafana/pyroscope/blob/main/operations/pyroscope/jsonnet/pyroscope-mixin/pyroscope-mixin/dashboards/pyroscope-reads.libsonnet#L19), while the monitoring is [deployed](https://github.com/grafana/pyroscope/blob/main/operations/pyroscope/helm/pyroscope/templates/servicemonitor.yaml) with `ServiceMonitor`, and the job names are service names.

#### To Reproduce
Steps to reproduce the behavior:
- deploy Pyroscope using Helm, enabling monitoring (`serviceMonitor.enabled: true`)
- generate dashboards and import them into Grafana

#### Expected behavior

Prometheus requests from the panels should be aligned with metrics from service monitors.

#### Environment

Kubernetes/Helm