The cluster/websocket tests were developed against websockets 14.2,
but Ubuntu and Alpine ship too old versions. Switch to installing
the latest version from pip instead, so we don't need to bother making
tests compatible with very old Python packages shipped by distributions.
This feels more like a band-aid solution - it still requires very manual
intervention to get the next builds, but at least this way we don't rely
on whatever Clang/libc++ happens to ship with FreeBSD for the only
libc++ testing. It seems like sanitizer builds don't use libc++, but I'd
rather a dedicated Linux/Clang/libc++ task at least.
The ccache version shipped with Ubuntu 24.04 does not yet recognize
--fprofile-update=atomic, install one that does.
Now that the asan_sanitizer build also includes building Spicy and
running the spicyz test suite, ccache is quite important.
Reference ccache/ccache#1408 and zeek/zeek#3777.
