deps: update llhttp to 2.0.1

Changelog:

• Optional SSE4.2 support (at compile time)
• Lenient mode of operation

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

cc @nodejs/http @addaleax @bnoordhuis