actions: twister: scale nodes up for large test coverage

If we determine we need more nodes than the default, do not override the
calculated number.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Author: nashif

scripts/ci/test_plan.py

@@ -331,7 +331,7 @@ def parse_args():
         if total_tests % args.tests_per_builder != total_tests:
             nodes = nodes + 1
 
-        if nodes > 5:
+        if args.default_matrix > nodes > 5:
             nodes = args.default_matrix
 
         tp.write(f"TWISTER_TESTS={total_tests}\n")