Istio version upgrade

We are using 1.6.7 version in OSDU, it's a little outdated and soon won't be supported by the latest deployable AKS version.

Upgrade details

• Current Version - 1.6.7
• New Version - 1.11.3

Steps to upgrade: Run osdu-istio pipeline to add in Gitops repo the updated manifests of Istio Operator, which takes care of upgrade.

https://dev.azure.com/ms-slb-cobuild/ms-slb-collab/_workitems/edit/665/