Update docstring in _channel_registry.py

Co-authored-by: daniel-zullo-frequenz <[email protected]>
Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/actor/_channel_registry.py

@@ -39,7 +39,7 @@ def set_resend_latest(self, key: str, resend_latest: bool) -> None:
         instructions.
 
         Args:
-            key: A key to identify the channel.
+            key: The key to identify the channel.
             resend_latest: Whether to resend the latest value to new receivers, for the
                 given channel.
         """