introspection: Use --include-uninstalled

For inter-module includes we need to use --include-uninstalled,
otherwise we may try to process pkg-config entries for uninstalled
.pc files.

Also:

* Don't include pangoft2 in its own package list.
* Filter out non-public pango-color-table.h

https://bugzilla.gnome.org/show_bug.cgi?id=630857