Stop stripping final newline

This setting was set in this tree for a very long time, but my editor
wasn't using it, so many files didn't respect this. Recently neovim
was updated to actually respect this setting, and these silly changes
started clogging my git diffs. I don't actually care anymore.

.editorconfig

@@ -3,6 +3,5 @@ root = true
 [*]
 charset = utf-8
 end_of_line = lf
-insert_final_newline = false
 indent_style = space
 indent_size = 4