MDEV-31835 Remove unnecessary extra HA_EXTRA_IGNORE_INSERT call

- This commit is different from 10.6 commit c438284863.
Due to Commit 045757af4c (MDEV-24621),
InnoDB does buffer and pre-sort the records for each index, and build
the indexes one page at a time.

Multiple large insert ignore statment aborts the server during bulk
insert operation. Problem is that InnoDB merge record exceeds
the page size. To avoid this scenario, InnoDB should catch
too big record while buffering the insert operation itself.

row_merge_buf_encode(): returns length of the encoded index record

row_merge_buf_write(): Catches the DB_TOO_BIG_RECORD earlier and
returns error

storage/mroonga/ha_mroonga.cpp

@@ -596,9 +596,6 @@ static const char *mrn_inspect_extra_function(enum ha_extra_function operation)
     inspected = "HA_EXTRA_NO_AUTOINC_LOCKING";
     break;
 #endif
-  case HA_EXTRA_IGNORE_INSERT:
-    inspected = "HA_EXTRA_IGNORE_INSERT";
-    break;
   }
   return inspected;
 }