Update aws-controllers-k8s/iam-chart Docker tag to v1.4.0

Author: renovate[bot]

gitops/addons/charts/gitops-bridge/values.yaml

@@ -1169,7 +1169,7 @@ addons:
     namespace: '{{ default "aws-controllers-k8s" (index .metadata.annotations "ack_iam_namespace")}}'
     chart: aws-controllers-k8s/iam-chart
     repoUrl: public.ecr.aws
-    targetRevision: "1.3.21"
+    targetRevision: "1.4.0"
     selector:
       matchExpressions:
         - key: enable_ack_iam