fix(ci-sizer): use getenv with default for SIZER_ALLOWED_ORG

Prevents gomplate crash when SIZER_ALLOWED_ORG is not set in environment.
Falls back to DevFW-CICD as default org.

template/stacks/ci-sizer/sizer-receiver/deployment.yaml

@@ -62,7 +62,7 @@ spec:
             - name: RECEIVER_SESSION_TTL
               value: "12h"
             - name: RECEIVER_ALLOWED_ORG
-              value: "{{{ .Env.SIZER_ALLOWED_ORG }}}"
+              value: "{{{ getenv "SIZER_ALLOWED_ORG" "DevFW-CICD" }}}"
             - name: RECEIVER_CPU_SIZING_MODE
               value: "observe"
             - name: RECEIVER_MEMORY_QOS