fix(helm): remove trim in priorityClassName conditional

[alirezadoostimehr]

Fix Helm generation of priorityClassName; chart failed to template/install when set

When .Values.operator.priorityClassName was set, the line injected by dev/generate_helm_chart.sh produced a malformed Go-template fragment, resulting in broken YAML. That made helm template/install fail.
This change fixes the issue and conditionally renders priorityClassName with proper quoting, so the chart templates and installs correctly whether the value is set or not.

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[alirezadoostimehr]

@Slach Thanks for the review and approval. The pipelines are complete and ready to merge.