weston: remove pipewire from PACKAGECONFIG

weston: remove pipewire from PACKAGECONFIG

Appending the pipewire feature to PACKAGECONFIG here is problematic
since it adds a dependency on meta-oe, breaking using meta-agl-core
on its own.  Remove it in favor of adding it in meta-agl-demo
instead.

Bug-AGL: SPEC-5325

Change-Id: I22f0c8dff578d70040786d96173e768d9cc2990a
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/30695
ci-image-build: Jenkins Job builder account
Tested-by: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account