test: make flaky crypto test more deterministic

Fixes: #14424
PR-URL: #14451
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

test/parallel/test-crypto-dh-leak.js

@@ -1,4 +1,4 @@
-// Flags: --expose-gc
+// Flags: --expose-gc --nocrankshaft --noconcurrent_recompilation
 'use strict';
 
 const common = require('../common');