Increase test engine version to fix 21.0 tests

I just tried building 21.0 which is a higher version than the one used
in the test data which broke this test.

This should be a high enough version to not break any time soon...

Author: asarium

test/test_data/mod/future_targetted_version/data/tables/test-mod.tbm

@@ -1,7 +1,7 @@
 #GAME SETTINGS
 
 $Target Version:
-    +Major: 20
+    +Major: 999
     +Minor: 5
     +Build: 10