test: remove --no-crankshaft

The option `--no-crankshaft` is no longer available as of V8 6.0

PR-URL: nodejs#14531
Reviewed-By: Evan Lucas <[email protected]>
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: Brian White <[email protected]>

Author: MylesBorins

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

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