cerbero: Update list of build tools
- Remove gobject-introspection.m4, vala.m4, and gtk-doc-lite since we've ported all GNOME recipes to meson
- m4 is only needed on macOS now
- Move gperf to platform-specific lists instead of being added by hand in init
- gettext-m4 and gettext-tools are not needed on Linux since we already install gettext-tools with the package manager
- pkg-config can be provided by the system on Linux, but we need it for pkg.m4, so it needs to be built
Also update gas-preprocessor commit.