Spread funrun load more (#25785)

GitOrigin-RevId: 055ea09a467108120df002c225deb3ac482137e2

Author: Preslav Le

crates/common/src/knobs.rs

@@ -839,7 +839,7 @@ pub static FUNRUN_FETCH_CLIENT_CACHE_SIZE: LazyLock<usize> =
 /// max_concurrent_mutations + max_concurrent_v8_actions < (number of funrun
 /// nodes - 1) * FUNRUN_CLIENT_MAX_CONCURRENT_REQUESTS_PER_UPSTREAM
 pub static FUNRUN_CLIENT_MAX_REQUESTS_PER_UPSTREAM: LazyLock<usize> =
-    LazyLock::new(|| env_config("FUNRUN_CLIENT_MAX_REQUESTS_PER_UPSTREAM", 25));
+    LazyLock::new(|| env_config("FUNRUN_CLIENT_MAX_REQUESTS_PER_UPSTREAM", 15));
 
 /// The maximum number of retries a Funrun client will perform. The client only
 /// retries overloaded errors.