fix: merge global labels with worker labels

values.yaml

labels:
  r1/component-id: "8"
  r1/contour: "rc10wb"

workers:
  manifest-management:
    additionalLabels:
      r1/component-id: "119"

worker will have following labels:

r1/component-id: "119"
r1/contour: "rc10wb"

You can test it with following values.yaml file: https://gitlab.trgdev.com/thor/r1legacy/main/-/blob/add-labels/helm-review-values.yml