Fix Since: tags for new API

https://github.com/behdad/harfbuzz/commit/e1d4d0f1dbd8518b5672245c05d73f22a9ed03ea#commitcomment-15006653

src/hb-font.cc

diff --git a/src/hb-font.cc b/src/hb-font.cc
index 3bd8e31..c038b10 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -577,7 +577,7 @@
  *
  * Return value:
  *
- * Since: 1.1.2
+ * Since: 1.1.3
  **/
 hb_bool_t
 hb_font_get_h_extents (hb_font_t *font,
@@ -595,7 +595,7 @@
  *
  * Return value:
  *
- * Since: 1.1.2
+ * Since: 1.1.3
  **/
 hb_bool_t
 hb_font_get_v_extents (hb_font_t *font,
@@ -836,7 +836,7 @@
  *
  *
  *
- * Since: 1.1.2
+ * Since: 1.1.3
  **/
 void
 hb_font_get_extents_for_direction (hb_font_t *font,