libwireplumber-0.4-dev: do not hardcode API version

This can be easily missed when upgrading the package, so it's safer to 
use a wildcard here as there won't be another 
`/usr/include/wireplumber-*` folder during build.

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>

debian/libwireplumber-0.4-dev.install

-usr/include/wireplumber-0.4
+usr/include/wireplumber-*
 usr/lib/*/libwireplumber*.so
 usr/lib/*/pkgconfig/wireplumber*
 /usr/share/gir-1.0/*.gir