LspDetach is now triggered by the main on_detach callback that is added
when an LSP client is attached to a buffer. The semantic_tokens module
already includes a LspDetach handler that does the right thing. When the
LspDetach trigger was added to the main LSP on_detach, it created a race
condition in semantic tokens when a buffer was deleted that would
trigger both its own on_detach and the LspDetach handlers. If the former
came last, an error was thrown trying to delete a non-existent augroup
(destroy() was being called twice).
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