Use gjs-internals.pc

Gjs changed to separate the "basic" API from "embedder" API.  Unfortunately
due to our use of the importer API and a few other bits, we need to use
the "module" one.  In the future I plan to extend the core API to
support this use case.

src/shell-global.c

@@ -23,7 +23,7 @@
 #include <gio/gio.h>
 #include <math.h>
 #include <X11/extensions/Xfixes.h>
-#include <gjs/gjs.h>
+#include <gjs/gjs-module.h>
 #include <canberra.h>
 #ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>