Fix deduplication when importing module statically and dynamically (#3297)
The `processed_assets` `IndexSet` was performing deduplication on the `AssetVc`, which is the same between static (`import ... from "foo"`) and dynamic (`import("foo")`) imports of the same specifier. But, the _reference_ to those assets is different, and generates different chunking semantics. In order for both to succeed, we need to process both assets.
Coupled with #3193's ability to load chunks on the server side, this fixes fixes WEB-381.