Update Istio to 1.11.3

Package Owner Merge Request

Package Changes

https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-controlplane/-/merge_requests/81

https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-controlplane/-/releases/1.11.3-bb.0

https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-operator/-/merge_requests/30

https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-operator/-/releases/1.11.3-bb.0

Closes https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/896

Also removed the keycloak image from synker cause its in CI now so we shouldn't need it there (see latest release images.txt, has two keycloak images - https://umbrella-bigbang-releases.s3-us-gov-west-1.amazonaws.com/umbrella/1.19.0/images.txt ).