[B4] List elements are not enclosed in parent elements on Widget Popular Contributors

This has already been reported many times on IC4.

Just for the record. There are more errors and warnings of this type.

These elements are already contained inside a <ul>, but since it has a role of tablist, Lighthouse expects role="tab" to be an immediate child (instead of the li).

I'll sort it out today 🤝

@Ehren thanks buddy 👀