Log Message:
Remove original OpenAL implementation (audio/openal).

As far as I can tell, no package is using this. They are all using
audio/openal-soft instead.

Brief history of OpenAL: This is the original reference implementation,
developed by Loki Software and Creative Labs. This was eventually made
proprietary, the open source version packaged here was discontinued, and
OpenAL-Soft was developed as a replacement. This package has pointed
to gentoo distfiles for about 10 years since the original distfiles
disappeared.

We've apparently been planning this since 2016 but nobody got around to it:

https://mail-index.netbsd.org/pkgsrc-users/2016/07/16/msg023531.html