Packages shipped with ESM shouldn't be prebundled

[yaquawa]

For example I'm using this package, which already support ESM module, but Vite is still going to prebundle it unless you put it in the optimizeDeps.exclude explicitly.

[patak-dev]

This is expected, Vite needs to pre-bundle dependencies by default to avoid bottlenecks when the browser requests too many files. It doesn't matter if it is ESM. If you would like to avoid pre-bundling a dependency, as you said, there is an option available.