Bump ACTS to v19.4.0

This bumps ACTS from v19.2.0 to v19.4.0.

Release notes of in-between versions: v19.3.0 and v19.4.0.

I'd merge this after !53807 (merged) preferably (CI tests)

Tagging @pagessin, @tbold, @lgagnon, @toyamaza, @asalzbur