fix(batch): force the results to be applied before closing the context

Author: bevzzz

src/test/java/io/weaviate/client6/v1/api/collections/batch/BatchContextTest.java

@@ -180,7 +180,7 @@ public void test_sendOneBatch() throws Exception {
     Assertions.assertThat(tasks)
         .extracting(TaskHandle::isAcked).allMatch(CompletableFuture::isDone);
 
-    out.beforeEof(new Event.Results(received, Collections.emptyMap()));
+    out.emitEvent(new Event.Results(received, Collections.emptyMap())).get();
 
     // Since MockServer runs in the same thread as this test,
     // the context will be updated before the last emitEvent returns.