DynamicProcessor: Fix typo in docstring

Author: plotski

prompt_toolkit/layout/processors.py

@@ -949,7 +949,7 @@ def __repr__(self) -> str:
 
 class DynamicProcessor(Processor):
     """
-    Processor class that can dynamically returns any Processor.
+    Processor class that dynamically returns any Processor.
 
     :param get_processor: Callable that returns a :class:`.Processor` instance.
     """