Only do ThreadPool worker tracking when the thread pool event source is enabled

[jkoritzinsky]

Per #47592 (comment), we should only do worker tracking when the thread pool event source and event sources in general are enabled.

cc: @marek-safar @eerhardt

Tagging subscribers to 'linkable-framework': @eerhardt, @vitek-karas, @LakshanF, @tannergooding, @sbomer
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Issue Details

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Per #47592 (comment), we should only do worker tracking when the thread pool event source and event sources in general are enabled.

cc: @marek-safar @eerhardt

Author:	jkoritzinsky
Assignees:	-
Labels:	area-System.Threading, linkable-framework
Milestone:	-

Tagging subscribers to 'size-reduction': @eerhardt, @SamMonoRT, @marek-safar, @tannergooding
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Per #47592 (comment), we should only do worker tracking when the thread pool event source and event sources in general are enabled.

cc: @marek-safar @eerhardt

Author:	jkoritzinsky
Assignees:	-
Labels:	area-System.Threading, size-reduction, untriaged
Milestone:	-