patch linestring_to_wire to re-use actual vertex

[MattFerraro]

So truck's behavior here is a little weird. For a wire to be closed, it requires that the start vertex and end vertex of a wire are exactly the same. It isn't sufficient for them to contain identical data, they must refer to the same piece of memory.

As implemented, a linestring describing a square creates 5 vertices, where the last and first are identical but not the same piece of memory. The fix here is to re-use the first vertex when creating the final edge.

[MattFerraro]

The failing third test is that we can no longer read and generate extrusions from project files which were generated before the great refactoring that replaced the old Sketch struct with the new ISOtope Sketch.

I can easily remake those project files once the UI is up and running again but for now I'd say let's just comment out the test and agree to revisit it again later

[av8ta]

I can easily remake those project files once the UI is up and running again but for now I'd say let's just comment out the test and agree to revisit it again later

@MattFerraro You can do this too: #[ignore = "test failing on CI"] and then we can go ahead and merge?

edit: don't worry I see you've already commented it out