[k8s] Remove chart from matchLabels in helper templates

[ddcprg]

This line will be prevent doing upgrades of the StatfulSet when a new version needs to be deployed

https://github.com/apache/pinot/blob/master/kubernetes/helm/pinot/templates/_helpers.tpl#L58

Kubernetes will fail with error

spec: Forbidden: updates to statefulset spec for fields other than 'replicas', 'template', and 'updateStrategy' are forbidden

[ivanvy-wix]

I think this issues refers to this line:

pinot/kubernetes/helm/pinot/templates/_helpers.tpl

Line 58 in bb25194

chart: {{ include "pinot.chart" . }}

The line has been removed in #7177 (with a way to keep compatibility with already deployed charts) and so the issue can be closed?