please modernize use of SWC

SWC has evolved, and it would be nice if this project was adapted to depend on newer stable v8 of swc_* crates.

Personally, my interest is in packaging this project for Debian, and Debian only rarely covers concurrent branches of crates.

I have tried to patch this project as shared here, but some tests fail and I am uncertain if that's unrelated or my patch is incomplete or even totally wrong.