Move lazy.nvim's own install outside the lazy plugin root so it's
treated as local and skipped during git-based lock file writes -
installing it as a tarball left it without a .git dir, which crashed
lazy's lock.update() on every sync (assert on Git.info of a non-git
dir).
Also patch nvim-treesitter's set-lang-from-mimetype! directive, which
crashes on any <script type="..."> tag because it reads match[id] as
a single node when Neovim core now always returns an array there.
Hooked on LazyDone so it overrides nvim-treesitter's own registration
instead of being clobbered by it. Added ruby/html/embedded_template
to ensure_installed so TSUpdate actually keeps those parsers current
instead of relying on one-time auto_install.
