controllers: properly check annotations at sts claim template

[f41gh7]

previously each pvc created by sts must be annotated with operator.victoriametrics.com/pvc-allow-volume-expansion now, it's no longer needed, operator performs a check on sts claim definition itself it allows to use it for PVC autoscaler or simmilar tool https://github.com/VictoriaMetrics/operator/issues/867