[BUG] javascript /= operator is parsed as regex by highlightingk

[SArpnt]

Version of Kakoune

v2023.07.29

Reproducer

create a file test.js

let foo = 20;
foo /= 3;
// all code here is higlighted incorrectly
foo /= 3;

Outcome

Expectations

the /= should be highlighted the same as *=, and highlighting between it should work
at the very least it would be good to make regex stop at the end of a line, javascript doesn't have multiline regexes.

Additional information

there are some other old similar issues but i haven't seen anything about this particular operator