patch 8.2.3187: Vim9: popup timer callback is not compiled

Problem:    Vim9: popup timer callback is not compiled.
Solution:   Compile the callback when creating the timer.

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3187,
 /**/
     3186,
 /**/