Skip thrift json roundtrip check while reading GroupByServingInfo (#774)

## Summary
When we add fields in our API, we can run into backwards / forwards
compat issues depending on when the json updates make their way out to
the GroupByServingInfo (on orch side / serving side). Turning off the
round trip check to help cut the noise on these issues. If we can
deserialize the thrift json we proceed else this code will throw a
JsonException.
Some details - [slack
thread](https://zipline-2kh4520.slack.com/archives/C08345NBWH4/p1747092844340579)

## Checklist
- [ ] Added Unit Tests
- [X] Covered by existing CI
- [ ] Integration tested
- [ ] Documentation update



<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Bug Fixes**
- Improved compatibility when loading certain configuration data by
relaxing validation during data processing.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: piyush-zlai

online/src/main/scala/ai/chronon/online/fetcher/MetadataStore.scala

@@ -412,7 +412,7 @@ class MetadataStore(fetchContext: FetchContext) {
         } else {
           import ai.chronon.online.metrics
           val groupByServingInfo = ThriftJsonCodec
-            .fromJsonStr[GroupByServingInfo](metaData.get, check = true, classOf[GroupByServingInfo])
+            .fromJsonStr[GroupByServingInfo](metaData.get, check = false, classOf[GroupByServingInfo])
           metrics.Metrics
             .Context(metrics.Metrics.Environment.MetaDataFetching, groupByServingInfo.groupBy)
             .withSuffix("group_by")