patch 9.0.1473: CI does not run sound tests

Problem:    CI does not run sound tests.
Solution:   Re-enable sound tests.  Use "apt-get" instead of "apt". (Ozaki
            Kiichi, closes #12280)

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1473,
 /**/
     1472,
 /**/