[bindings] Use hb_glib_blob_create() in sample

hb_blob_create() is considered C-only API.

src/hb-blob.cc

diff --git a/src/hb-blob.cc b/src/hb-blob.cc
index 51ea20d..8759a25 100644
--- a/src/hb-blob.cc
+++ b/src/hb-blob.cc
@@ -78,12 +78,12 @@
 }
 
 /**
- * hb_blob_create: (Xconstructor)
- * @data: (array length=length) (element-type uint8_t) (closure user_data) (destroy destroy) (scope notified) (transfer none): Pointer to blob data.
+ * hb_blob_create: (skip)
+ * @data: Pointer to blob data.
  * @length: Length of @data in bytes.
  * @mode: Memory mode for @data.
- * @user_data: (nullable): Data parameter to pass to @destroy.
- * @destroy: (nullable): Callback to call when @data is not needed anymore.
+ * @user_data: Data parameter to pass to @destroy.
+ * @destroy: Callback to call when @data is not needed anymore.
  *
  * Creates a new "blob" object wrapping @data.  The @mode parameter is used
  * to negotiate ownership and lifecycle of @data.