roachtest/asyncpg: ignore flaky TestExecuteMany test

The asyncpg test
```
test_execute.TestExecuteMany.test_executemany_server_failure_during_writes
```
has been observed to be flaky.

This change adds the test to the ignore list.

Fixes: #151024
Epic: none
Release note: none

Author: spilchen

pkg/cmd/roachtest/tests/asyncpg_blocklist.go

@@ -69,20 +69,21 @@ var asyncpgBlocklist = blocklist{
 }
 
 var asyncpgIgnoreList = blocklist{
-	`test_pool.TestPool.test_pool_01`:                                   "can't parse output",
-	`test_copy.TestCopyFrom.test_copy_from_query_basics`:                "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyFrom.test_copy_from_query_cancellation_explicit`: "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyFrom.test_copy_from_query_timeout_1`:             "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyFrom.test_copy_from_query_to_sink`:               "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyFrom.test_copy_from_table_large_rows`:            "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_records_to_table_1`:                 "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_records_to_table_no_binary_codec`:   "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_basics`:                    "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_fail_in_source_1`:          "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_fail_in_source_2`:          "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_from_bytes_like`:           "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_from_file_path`:            "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_large_rows`:                "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_copy.TestCopyTo.test_copy_to_table_timeout`:                   "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
-	`test_listeners.TestListeners.test_dangling_listener_warns`:         "flaky",
+	`test_pool.TestPool.test_pool_01`:                                            "can't parse output",
+	`test_copy.TestCopyFrom.test_copy_from_query_basics`:                         "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyFrom.test_copy_from_query_cancellation_explicit`:          "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyFrom.test_copy_from_query_timeout_1`:                      "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyFrom.test_copy_from_query_to_sink`:                        "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyFrom.test_copy_from_table_large_rows`:                     "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_records_to_table_1`:                          "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_records_to_table_no_binary_codec`:            "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_basics`:                             "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_fail_in_source_1`:                   "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_fail_in_source_2`:                   "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_from_bytes_like`:                    "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_from_file_path`:                     "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_large_rows`:                         "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_copy.TestCopyTo.test_copy_to_table_timeout`:                            "flaky; see #119291 and https://github.com/MagicStack/asyncpg/issues/240",
+	`test_execute.TestExecuteMany.test_executemany_server_failure_during_writes`: "flaky",
+	`test_listeners.TestListeners.test_dangling_listener_warns`:                  "flaky",
 }