Fix: add policy binding for forgebot K8s auth role

Every K8s auth role needs at least one entry in the policy_auth_map.
Add a policy granting the forgebot role read access to the namespace-
scoped KV path, which the operator SA needs when authenticating with
the forgebot role instead of the default role.

policies/kv/service/forgebot/config/read.yaml

@@ -0,0 +1,9 @@
+---
+rules:
+  - path: "kv/data/kubernetes/namespace/forgebot/*"
+    capabilities:
+      - read
+
+auth:
+  k8s/au/syd1:
+    - forgebot