Update gp2 to gp3 in AWS storage class example

Author: marcleblanc2

charts/sourcegraph/examples/aws/override.yaml

@@ -10,7 +10,7 @@ frontend:
 
 storageClass:
   create: true
-  type: gp2 # This configures SSDs (recommended).
+  type: gp3 # This configures SSDs (recommended).
   provisioner: ebs.csi.aws.com
   volumeBindingMode: WaitForFirstConsumer
   reclaimPolicy: Retain