CCM-12614: update to retryCount description

Author: Ian-Hodges

src/cloudevents/domains/digital-letters/2025-10-draft/defs/pdm.schema.yaml

@@ -12,6 +12,6 @@ properties:
   retryCount:
     type: integer
     minimum: 0
-    description: Number of times that PDM has been polled while waiting for document processing to complete
+    description: Number of times that PDM has been retried while waiting for document processing to complete
     examples:
       - 2