style(cache): replace pass with ellipsis in abstract methods (#1455)

Updates abstract method implementations in CacheInterface to use ellipsis (...) instead of pass, following modern Python conventions for abstract method stubs.

Author: Pouyanpi

nemoguardrails/llm/cache/interface.py

@@ -44,7 +44,7 @@ def get(self, key: Any, default: Any = None) -> Any:
         Returns:
             The value associated with the key, or default if not found.
         """
-        pass
+        ...
 
     @abstractmethod
     def put(self, key: Any, value: Any) -> None:
@@ -58,7 +58,7 @@ def put(self, key: Any, value: Any) -> None:
             key: The key to store.
             value: The value to associate with the key.
         """
-        pass
+        ...
 
     @abstractmethod
     def size(self) -> int:
@@ -68,7 +68,7 @@ def size(self) -> int:
         Returns:
             The number of items currently stored in the cache.
         """
-        pass
+        ...
 
     @abstractmethod
     def is_empty(self) -> bool:
@@ -78,7 +78,7 @@ def is_empty(self) -> bool:
         Returns:
             True if the cache contains no items, False otherwise.
         """
-        pass
+        ...
 
     @abstractmethod
     def clear(self) -> None:
@@ -87,7 +87,7 @@ def clear(self) -> None:
 
         After calling this method, the cache should be empty.
         """
-        pass
+        ...
 
     def contains(self, key: Any) -> bool:
         """
@@ -115,7 +115,7 @@ def maxsize(self) -> int:
         Returns:
             The maximum number of items the cache can hold.
         """
-        pass
+        ...
 
     def get_stats(self) -> dict:
         """