DOCS: Add missing periods (#75407)

* Add missing period at end of sentence

* Add missing period

Co-authored-by: LamTrinh.Dev <[email protected]>

---------

Co-authored-by: LamTrinh.Dev <[email protected]>

Author: amartini51

stdlib/public/Concurrency/DiscardingTaskGroup.swift

@@ -52,7 +52,7 @@ import Swift
 /// If you call `addTask(priority:operation:)` to create a new task in a canceled group,
 /// that task is immediately canceled after creation.
 /// Alternatively, you can call `asyncUnlessCancelled(priority:operation:)`,
-/// which doesn't create the task if the group has already been canceled
+/// which doesn't create the task if the group has already been canceled.
 /// Choosing between these two functions
 /// lets you control how to react to cancellation within a group:
 /// some child tasks need to run regardless of cancellation,
@@ -550,7 +550,7 @@ extension DiscardingTaskGroup: Sendable { }
 /// If you call `addTask(priority:operation:)` to create a new task in a canceled group,
 /// that task is immediately canceled after creation.
 /// Alternatively, you can call `asyncUnlessCancelled(priority:operation:)`,
-/// which doesn't create the task if the group has already been canceled
+/// which doesn't create the task if the group has already been canceled.
 /// Choosing between these two functions
 /// lets you control how to react to cancellation within a group:
 /// some child tasks need to run regardless of cancellation,
@@ -713,7 +713,7 @@ public func _unsafeInheritExecutor_withThrowingDiscardingTaskGroup<GroupResult>(
 /// however a discarding group cannot poll child tasks for results and therefore assumes that child
 /// task throws are an indication of a group wide failure. In order to avoid such behavior,
 /// use a ``DiscardingTaskGroup`` instead of a throwing one, or catch specific errors in
-/// operations submitted using `addTask`
+/// operations submitted using `addTask`.
 ///
 /// Since a `ThrowingDiscardingTaskGroup` is a structured concurrency primitive, cancellation is
 /// automatically propagated through all of its child-tasks (and their child

stdlib/public/Concurrency/TaskGroup.swift

@@ -50,7 +50,7 @@ import Swift
 /// If you call `addTask(priority:operation:)` to create a new task in a canceled group,
 /// that task is immediately canceled after creation.
 /// Alternatively, you can call `addTaskUnlessCancelled(priority:operation:)`,
-/// which doesn't create the task if the group has already been canceled
+/// which doesn't create the task if the group has already been canceled.
 /// Choosing between these two functions
 /// lets you control how to react to cancellation within a group:
 /// some child tasks need to run regardless of cancellation,
@@ -161,7 +161,7 @@ public func _unsafeInheritExecutor_withTaskGroup<ChildTaskResult, GroupResult>(
 /// If you call `addTask(priority:operation:)` to create a new task in a canceled group,
 /// that task is immediately canceled after creation.
 /// Alternatively, you can call `addTaskUnlessCancelled(priority:operation:)`,
-/// which doesn't create the task if the group has already been canceled
+/// which doesn't create the task if the group has already been canceled.
 /// Choosing between these two functions
 /// lets you control how to react to cancellation within a group:
 /// some child tasks need to run regardless of cancellation,