webrtc-sys-build: bump zip to 9.0.4 for security advisories

[drendog]

the zip crate maintainer yanked all older releases because of 3 security advisories, and while 0.6 was yanked I couldn't use the SDK. It has been un-yanked since, but can still flags it and it could be yanked again, so this moves to 9.0.4

zip-rs/zip2#1075

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}