gobject-introspection: update to 1.60.2.

1.60.2 - 2019-06-15
-------------------

* docwriter: Fix Exception message attribute :mr:`146` (:user:`Philip Chimento <ptomato>`)
* meson: fix default cairo DLL name on Windows
* scanner: Fix error on Windows in case source files are on different drives
* gi-test: Fix gir file tests with MSVC :mr:`151` (:user:`Chun-wei Fan <fanc999>`)
* MSVC.README.rst: Update VS 2008/x64 build notes :mr:`152` (:user:`Chun-wei Fan <fanc999>`)
* giscanner/scannerlexer.l: Include io.h on Windows (:user:`Chun-wei Fan <fanc999>`)
* build: Force-include msvc_recommended_pragmas.h on Visual Studio :mr:`152` (:user:`Chun-wei Fan <fanc999>`)
* Update glib annotations (2.60.4)

(wiz)