Update TaskAwaiter`1.xml

[JimDaly]

Summary

Describe your changes here.

Per comments in #7941 , removing remarks that say 'This method is intended for compiler use rather than for use in application code.'

At this point, the right thing for TaskAwaiter and TaskAwaiter is probably to just strike those sentence from the docs, though some extra verbiage around the distinction from Task.Wait would be welcome

[gewarren]

Related to #7969.

[opbld34]

Docs Build status updates of commit da8b8b1:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/System.Runtime.CompilerServices/TaskAwaiter`1.xml	✅Succeeded	View

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the docs.microsoft.com contributor guides
• Post your question in the Docs support channel

[gewarren]

Closing in favor of #7968.