Fix a possible typo (#1762)

(cherry picked from commit d0b1444393d9e209307dcad066cb8d19a667eda9)

Author: yuanhang

Sources/ComposableArchitecture/Effects/Cancellation.swift

@@ -166,7 +166,7 @@ extension EffectProducer {
 
 /// Execute an operation with a cancellation identifier.
 ///
-/// If the operation is in-flight when `Task.cancel(id:)` is called with the same identifier, or
+/// If the operation is in-flight when `Task.cancel(id:)` is called with the same identifier, the
 /// operation will be cancelled.
 ///
 /// ```