GDBusActionGroup: drop ability to 'inject'

Also drop the GDBusActionGroupFlags that were only meant to facilitate
injection-based usage.

gio/gioenums.h

@@ -1517,25 +1517,6 @@ typedef enum {
   G_IO_MODULE_SCOPE_BLOCK_DUPLICATES
 } GIOModuleScopeFlags;
 
-/* GDBusActionGroupFlags:
- * @G_DBUS_ACTION_GROUP_FLAGS_NONE: No flags set.
- * @G_DBUS_ACTION_GROUP_FLAGS_DO_NOT_POPULATE: Do not make the initial
- *   D-Bus call to populate the set of actions in the group.  Instead,
- *   actions can be added using g_dbus_action_group_inject().  Changes
- *   are still monitored.
- * @G_DBUS_ACTION_GROUP_FLAGS_DO_NOT_WATCH: Don't watch for changes.
- *
- * Flags used when constructing a #GDBusActionGroup.
- *
- * Since: 2.30
- **/
-typedef enum
-{
-  G_DBUS_ACTION_GROUP_FLAGS_NONE            = 0,
-  G_DBUS_ACTION_GROUP_FLAGS_DO_NOT_POPULATE = (1<<0),
-  G_DBUS_ACTION_GROUP_FLAGS_DO_NOT_WATCH    = (1<<1)
-} GDBusActionGroupFlags;
-
 G_END_DECLS
 
 #endif /* __GIO_ENUMS_H__ */