add due date

Author: mfori

sources/platform/actors/development/actor_definition/input_schema/specification.md

@@ -979,10 +979,12 @@ This setting defines runtime access only and doesn't change field visibility or
 
 ### Deprecation of `patternKey` and `patternValue`
 
-The following properties are deprecated and will be removed in a future version:
+::::warning Deprecation notice
+**The following properties are deprecated and will continue to be supported until May 31, 2026:**
 
 - `patternKey` - Used to validate keys in objects and arrays
 - `patternValue` - Used to validate values in objects and arrays
+::::
 
 We are deprecating these properties to better align with the JSON schema specification. The current approach with `patternKey` and `patternValue` is Apify-specific and doesn't follow standard JSON schema validation patterns. By moving to standard JSON schema, we provide a more consistent experience that matches industry standards while enabling more powerful validation capabilities through the ability to define sub-properties.