Problem: Loading `vim.fs` via the `vim.loader` Lua package loader will
result in a stack overflow due to a cyclic dependency. This may happen
when the `vim.fs` module isn't byte-compiled, i.e. when `--luamod-dev`
is used (#27413).
Solution: `vim.loader` depends on `vim.fs`. Therefore `vim.fs` should
be loaded in advance.
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