[jaeger] Add kubeVersion to indicate Kubernetes compatibility (#449)

Prior to this commit helm could determine, prior to an apply, whether
the chart is compatible with the local Kubernetes cluster.

After this commit helm is able to reject the apply immediately.

Signed-off-by: Jesse Hathaway <jhathaway@wikimedia.org>

charts/jaeger/Chart.yaml

@@ -3,7 +3,9 @@ appVersion: 1.39.0
 description: A Jaeger Helm chart for Kubernetes
 name: jaeger
 type: application
-version: 0.67.2
+version: 0.67.3
+# CronJobs require v1.21
+kubeVersion: '>= 1.21'
 keywords:
   - jaeger
   - opentracing