frontend: Add defunct Twitch Soundtrack plugin to DLL blocklist

[derrod]

Description

Blacklists the defunct Twitch Soundtrack app's plugin from loading.

Motivation and Context

Breaks VOD track, see #13636

How Has This Been Tested?

Hasn't, the app is long gone and I didn't want to find a random download just to test this. Since we know the DLL name from above issue's log this should probably be good enough though.

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code is not on the master branch.
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[Fenrirthviti]

Shame we can't link any kind of official announcement as all the pages that talked about support being discontinued are no longer valid, but this seems just fine.