Makefile: Remove long micropython test from check_light

It takes a very long time, so remove it from the "light" check.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Makefile

@@ -291,7 +291,7 @@ check_vunit:
 
 check: $(tests) tests_console test_micropython test_micropython_long tests_unit
 
-check_light: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 test_micropython test_micropython_long tests_console tests_unit
+check_light: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 test_micropython tests_console tests_unit
 
 $(tests): core_tb
 	@./scripts/run_test.sh $@