fix pgcopydb seg fault and -c idle_in_transaction_session_timeout=0 (#10692)

## Problem

During ingest_benchmark which uses `pgcopydb`
([see](https://github.com/dimitri/pgcopydb))we sometimes had outages.
- when PostgreSQL COPY step failed we got a segfault (reported
[here](https://github.com/dimitri/pgcopydb/issues/899))
- the root cause was Neon idle_in_transaction_session_timeout is set to
5 minutes which is suboptimal for long-running tasks like project import
(reported [here](https://github.com/dimitri/pgcopydb/issues/900))

## Summary of changes

Patch pgcopydb to avoid segfault.
override idle_in_transaction_session_timeout and set it to "unlimited"

test_runner/performance/test_perf_ingest_using_pgcopydb.py

@@ -136,7 +136,7 @@ def run_command_and_log_output(command, log_file_path: Path):
         "LD_LIBRARY_PATH": f"{os.getenv('PGCOPYDB_LIB_PATH')}:{os.getenv('PG_16_LIB_PATH')}",
         "PGCOPYDB_SOURCE_PGURI": cast(str, os.getenv("BENCHMARK_INGEST_SOURCE_CONNSTR")),
         "PGCOPYDB_TARGET_PGURI": cast(str, os.getenv("BENCHMARK_INGEST_TARGET_CONNSTR")),
-        "PGOPTIONS": "-c maintenance_work_mem=8388608 -c max_parallel_maintenance_workers=7",
+        "PGOPTIONS": "-c idle_in_transaction_session_timeout=0 -c maintenance_work_mem=8388608 -c max_parallel_maintenance_workers=7",
     }
     # Combine the current environment with custom variables
     env = os.environ.copy()