girrepository: Replace usage of gsize with standard size_t

We just do a safe s/gsize/size_t/ replacement here without doing any
changes to places in which different size of size_t and gsize may be
actually different and create troubles.

girepository/givfuncinfo.h

@@ -64,9 +64,9 @@ GI_AVAILABLE_IN_ALL
 gboolean          gi_vfunc_info_invoke      (GIVFuncInfo      *info,
                                              GType             implementor,
                                              const GIArgument *in_args,
-                                             gsize             n_in_args,
+                                             size_t            n_in_args,
                                              GIArgument       *out_args,
-                                             gsize             n_out_args,
+                                             size_t            n_out_args,
                                              GIArgument       *return_value,
                                              GError          **error);