test: fix expectWarning conflict in test-crypto-hmac

The existing inline `expectWarning` block at the bottom of the file
overwrites the top-of-file registration added by the previous commit,
because `expectWarning` stores expectations keyed by warning name
(`DeprecationWarning`) and the second call replaces the first.

Consolidate both DEP0181 and DEP0206 expectations into the single
top-of-file call and drop the now-redundant inline block. The
`crypto.Hmac('sha256', 'Node')` call earlier in the file already
exercises the constructor-without-`new` path that triggers DEP0181.

Author: soulee-dev

test/parallel/test-crypto-hmac.js

@@ -9,6 +9,7 @@ const crypto = require('crypto');
 
 common.expectWarning({
   DeprecationWarning: {
+    DEP0181: 'crypto.Hmac constructor is deprecated.',
     DEP0206: 'Calling digest() on an already-finalized Hmac instance is deprecated.',
   },
 });
@@ -466,13 +467,3 @@ assert.strictEqual(
     crypto.createHmac('sha256', keyObject).update('foo').digest(),
   );
 }
-
-{
-  crypto.Hmac('sha256', 'Node');
-  common.expectWarning({
-    DeprecationWarning: [
-      ['crypto.Hmac constructor is deprecated.',
-       'DEP0181'],
-    ]
-  });
-}