Merge branch 'update-istio-operator-tag-1.15.3-bb.0' into 'master'

Update Istio to 1.15.3 (+ TID to 1.15.1)

Closes platform-one/big-bang/apps/core/istio-controlplane#86 and platform-one/big-bang/apps/core/istio-operator#38

See merge request platform-one/big-bang/bigbang!2242

chart/values.yaml

@@ -128,7 +128,7 @@ istio:
   git:
     repo: https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-controlplane.git
     path: "./chart"
-    tag: "1.15.0-bb.1"
+    tag: "1.15.3-bb.0"
 
   # -- Tetrate Istio Distribution - Tetrate provides FIPs verified Istio and Envoy software and support,
   # validated through the FIPs Boring Crypto module. Find out more from Tetrate - https://www.tetrate.io/tetrate-istio-subscription
@@ -244,7 +244,7 @@ istiooperator:
   git:
     repo: https://repo1.dso.mil/platform-one/big-bang/apps/core/istio-operator.git
     path: "./chart"
-    tag: "1.15.0-bb.1"
+    tag: "1.15.3-bb.0"
 
   # -- Flux reconciliation overrides specifically for the Istio Operator Package
   flux: {}