Suppress dead_code warning in test struct

The PartialRead struct fields using IgnoredAny are intentionally
not read - they exist to test that the deserializer correctly
skips fields during deserialization.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: oschwald

src/reader_test.rs

@@ -1213,6 +1213,7 @@ fn test_ignored_any() {
 
     // Struct that only reads some fields, ignoring others via IgnoredAny
     #[derive(Deserialize, Debug)]
+    #[allow(dead_code)]
     struct PartialRead {
         utf8_string: String,
         // These fields use IgnoredAny to skip decoding