Support `allowNamespaces` and `denyNamespaces` in `targetAllocator.prometheusCR` for `opentelemetry-kube-stack`

[lexicoder]

I'd like to request support for the denyNamespaces and allowNamespaces fields under targetAllocator.prometheusCR in the opentelemetry-kube-stack Helm chart.

Use case

When deploying the chart, I need to exclude specific namespaces from being scraped by the collector via the Target Allocator. The OpenTelemetry Operator supports this functionality, but the opentelemetry-kube-stack chart does not currently support passing these fields into the generated OpenTelemetryCollector custom resource.

Expected behaviour

I would expect to be able to set the following values in the values.yaml:

collectors:
  scraper:
    targetAllocator:
      prometheusCR:
        denyNamespaces:
          - namespace-1
        allowNamespaces:
          - namespace-2

Proposed improvement

Update the chart to allow setting allowNamespaces and denyNamespaces under targetAllocator.prometheusCR in the values.yaml.