Mismatch between PowerShell vcpkg tool reported version and actual version provided

**Describe the bug** See https://github.com/microsoft/vcpkg/blob/master/scripts/vcpkg-tools.json#L316 7.5.4 vs. what is actually downloaded: 7.6.1 Seems just like a forgotten update on version bump? Don't think it's intentional. @BillyONeal