Add some checks for kafkaJS compability mode

Author: milindl

lib/kafkajs/_consumer.js

@@ -343,7 +343,7 @@ class Consumer {
         try {
           if (err.code === LibrdKafkaError.codes.ERR__ASSIGN_PARTITIONS) {
 
-            if (this.#checkPendingSeeks)
+            if (this.#checkPendingSeeks && this.#kafkaJSCompatibilityMode)
               assignment = this.#assignAsPerSeekedOffsets(assignment);
 
             this.#internalClient.assign(assignment);
@@ -1099,9 +1099,10 @@ class Consumer {
     this.#checkPendingSeeks = true;
     this.#pendingSeeks.set(`${rdKafkaTopicPartitionOffset.topic}|${rdKafkaTopicPartitionOffset.partition}`, rdKafkaTopicPartitionOffset.offset);
 
-    /* Immediately realize the seek if we're not in compatibility mode. */
+    /* Immediately realize the seek if we're not in compatibility mode. And clear pending seeks.
+     * We don't need them for rebalance. */
     if (!this.#kafkaJSCompatibilityMode) {
-      return this.#seekInternal();
+      return this.#seekInternal().then(() => this.#pendingSeeks.clear());
     }
   }