docs: Add missing Since annotations

gtk/gtkalertdialog.c

@@ -38,7 +38,7 @@
  * If you don't need to wait for a button to be clicked, you can use
  * [method@Gtk.AlertDialog.show].
  *
- * `GtkAlertDialog was added in GTK 4.10.
+ * Since: 4.10
  */
 
 /* {{{ GObject implementation */
@@ -402,7 +402,7 @@ gtk_alert_dialog_set_message (GtkAlertDialog *self,
 
   if (g_strcmp0 (self->message, message) == 0)
     return;
- 
+
   new_message = g_strdup (message);
   g_free (self->message);
   self->message = new_message;

gtk/gtkcolordialog.c

@@ -43,7 +43,7 @@
  * See [class@Gtk.ColorDialogButton] for a convenient control
  * that uses `GtkColorDialog` and presents the results.
  *
- * `GtkColorDialog was added in GTK 4.10.
+ * Since: 4.10
  */
 /* {{{ GObject implementation */
 

gtk/gtkcolordialogbutton.c

@@ -70,6 +70,8 @@ static void     update_button_sensitivity
  * `GtkColorDialogButton` has a single CSS node with name colorbutton which
  * contains a button node. To differentiate it from a plain `GtkButton`,
  * it gets the .color style class.
+ *
+ * Since: 4.10
  */
 
 /* {{{ GObject implementation */

gtk/gtkfiledialog.c

@@ -40,7 +40,7 @@
  * the corresponding finish function, for example
  * [method@Gtk.FileDialog.open_finish].
  *
- * `GtkFileDialog was added in GTK 4.10.
+ * Since: 4.10
  */
 
 /* {{{ GObject implementation */

gtk/gtkfontdialog.c

@@ -44,7 +44,7 @@
  * See [class@Gtk.FontDialogButton] for a convenient control
  * that uses `GtkFontDialog` and presents the results.
  *
- * `GtkFontDialog was added in GTK 4.10.
+ * Since: 4.10
  */
 
 /* {{{ GObject implementation */

gtk/gtkfontdialogbutton.c

@@ -57,6 +57,8 @@ static void     update_button_sensitivity
  *
  * `GtkFontDialogButton` has a single CSS node with name fontbutton which
  * contains a button node with the .font style class.
+ *
+ * Since: 4.10
  */
 
 /* {{{ GObject implementation */