k/group: do not log ignoring raft configuration batches

Raft configuration batches are integral part of Raft managed log.
Emitting warn log message that Redpanda ignore them when parsing
consumer group state machine data may be confusing as this is expected
and not something that the users should worry about.

Signed-off-by: Michał Maślanka <michal@redpanda.com>

src/v/kafka/server/group_data_parser.h

@@ -16,6 +16,7 @@
 #include "kafka/server/group_metadata.h"
 #include "kafka/server/logger.h"
 #include "model/record.h"
+#include "model/record_batch_types.h"
 
 template<typename T>
 T parse_tx_batch(const model::record_batch& batch, int8_t version) {
@@ -81,6 +82,10 @@ class group_data_parser {
         if (b.header().type == model::record_batch_type::raft_data) {
             return handle_raft_data(std::move(b));
         }
+        // silently ignore raft configuration.
+        if (b.header().type == model::record_batch_type::raft_configuration) {
+            return ss::now();
+        }
         if (b.header().type == model::record_batch_type::group_prepare_tx) {
             auto data = parse_tx_batch<kafka::group_tx::offsets_metadata>(
               b, group::prepared_tx_record_version);