chore: adjust serializer log wording

Co-authored-by: afarntrog <47332252+afarntrog@users.noreply.github.com>

Author: Copilot

src/strands/types/state_serializers.py

@@ -48,7 +48,7 @@ def serialize(self, state: Mapping[str, Any]) -> dict[str, Any]:
     def deserialize(self, payload: Mapping[str, Any]) -> dict[str, Any]:
         """Deserialize JSON-friendly dict."""
         if not isinstance(payload, Mapping):
-            logger.debug("state_deserialize_error=<non-mapping> | expected mapping payload for json serializer")
+            logger.debug("state_deserialize_error=<non-mapping> | expected mapping payload for JSON serializer")
             return {}
         return dict(payload)
 
@@ -72,10 +72,10 @@ def serialize(self, state: Mapping[str, Any]) -> dict[str, Any]:
     def deserialize(self, payload: Mapping[str, Any]) -> dict[str, Any]:
         """Deserialize pickle-based payload."""
         if not isinstance(payload, Mapping):
-            logger.debug("state_deserialize_error=<non-mapping> | expected mapping payload for pickle serializer")
+            logger.debug("state_deserialize_error=<non-mapping> | expected mapping payload for Pickle serializer")
             return {}
         if payload.get(self._SERIALIZER_KEY) != self.name or self._PAYLOAD_KEY not in payload:
-            logger.debug("state_deserialize_error=<invalid-metadata> | missing pickle serializer markers")
+            logger.debug("state_deserialize_error=<invalid-metadata> | missing Pickle serializer markers")
             return {}
         try:
             return pickle.loads(base64.b64decode(str(payload[self._PAYLOAD_KEY])))