fix: Buffer size error with DSL migration calls (#34905)

**/test sanity**



<!-- This is an auto-generated comment: Cypress test results  -->
> [!TIP]
> 🟢 🟢 🟢 All cypress tests have passed! 🎉 🎉 🎉
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/9907267253>
> Commit: 954c3e7
> <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=9907267253&attempt=1"
target="_blank">Cypress dashboard</a>.
> Tags: `@tag.Sanity`
> Spec:
> <hr>Fri, 12 Jul 2024 12:00:55 UTC
<!-- end of auto-generated comment: Cypress test results  -->

app/server/appsmith-server/src/main/java/com/appsmith/server/helpers/RTSCaller.java

@@ -8,6 +8,7 @@
 import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.stereotype.Component;
 import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.ExchangeStrategies;
 import org.springframework.web.reactive.function.client.WebClient;
 import reactor.core.publisher.Mono;
 import reactor.netty.http.client.HttpClient;
@@ -28,6 +29,8 @@ public class RTSCaller {
     @Value("${appsmith.rts.port:}")
     private String rtsPort;
 
+    private static final int MAX_IN_MEMORY_SIZE_IN_BYTES = 16 * 1024 * 1024;
+
     @PostConstruct
     private void makeWebClient() {
         if (isEmpty(rtsPort)) {
@@ -45,6 +48,9 @@ private void makeWebClient() {
         // We do NOT use `WebClientUtils` here, intentionally, since we don't allow connections to 127.0.0.1,
         // which is exactly the _only_ host we want to hit from here.
         webClient = WebClient.builder()
+                .exchangeStrategies(ExchangeStrategies.builder()
+                        .codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(MAX_IN_MEMORY_SIZE_IN_BYTES))
+                        .build())
                 .clientConnector(new ReactorClientHttpConnector(HttpClient.create(connectionProvider)))
                 .baseUrl("http://127.0.0.1:" + rtsPort)
                 .build();