Fix: Force Close when Rearranging Pin items in side bar

[ChengYi0224]

Resolved / Related Issues

To prevent extra work, all changes to the Files codebase must link to an approved issue marked as Ready to build. Please insert the issue number following the hashtag with the issue number that this Pull Request resolves.

• Closes Bug: Force Close when Rearranging Pin items in side bar #16808

Steps used to test these changes

1. Open Files
2. In Pinned scroller, right click a testing folder.
3. Left click "unpin from sidebar" and see if it is removed properly.

[yaira2]

@ChengYi0224 thank you for the PR. Can you clarify how this resolves #16808? This issue is regarding the feature to reorder pinned items, as far as I can tell, there isn't any connection with pinning and unpinning items.

[ChengYi0224]

Thank you for reviewing this PR. I should clarify that this change may not directly resolve issue #16808 regarding reordering pinned items.

I encountered a threading-related issue when working with pinned items, specifically with the unpinfromhome verb, which led me to submit this PR after discussion with a developer in Discord. The issue I experienced was triggered by an external application (OneDrive) interacting with explorer services.

While my PR ensures the fi.InvokeVerb("unpinfromhome") call runs within an STA context, I now realize it's not directly addressing the reordering functionality described in #16808. I apologize for the confusion.