Limit edit prediction reject batches to max (#43965)

We currently attempt to flush all rejected predictions at once even if
we have accumulated more than
`MAX_EDIT_PREDICTION_REJECTIONS_PER_REQUEST`. Instead, we will now flush
as many as possible, and then keep the rest for the next batch.


Release Notes:

- N/A

crates/cloud_llm_client/src/cloud_llm_client.rs

@@ -206,11 +206,16 @@ pub struct AcceptEditPredictionBody {
     pub request_id: String,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Deserialize)]
 pub struct RejectEditPredictionsBody {
     pub rejections: Vec<EditPredictionRejection>,
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub struct RejectEditPredictionsBodyRef<'a> {
+    pub rejections: &'a [EditPredictionRejection],
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct EditPredictionRejection {
     pub request_id: String,