PG DataSource Error handler throwing memory leak warning

Steps to reproduce

• Add onError handler in DataSource for Loopback Connector Postgresql.
• Use DataSource on frequent manner.
• It should throw warnings like
  (node:80014) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [Client]. Use emitter.setMaxListeners() to increase limit

(More details to reproduce the issue are provided in the README.md file in the sandbox repository)

Current Behavior

It doesn't remove the attached error event listeners while releasing the connection back to pool.

Expected Behavior

It should remove attached event listener before releasing connection back to pool.

Link to reproduction sandbox

https://github.com/vinod-hansda/loopback-pg-warning

Additional information

node -e 'console.log(process.platform, process.arch, process.versions.node)' :-
darwin arm64 18.20.6

npm ls --prod --depth 0 | grep loopback :-
npm warn config production Use --omit=dev instead.
loopback-pg@0.0.1 /Users/vinodhansda/Documents/GitHub/loopback-pg-warning
├── @loopback/boot@5.0.10
├── @loopback/core@4.0.10
├── @loopback/repository@5.1.5
├── @loopback/rest-explorer@5.0.10
├── @loopback/rest@12.0.10
├── @loopback/service-proxy@5.0.10
├── loopback-connector-postgresql@7.1.9

Related Issues

See Reporting Issues for more tips on writing good issues

使用链接的 sandbox 及其 README，通过 PostgreSQL DataSource 和 onError 处理程序重现 MaxListenersExceededWarning。然后检查 connector 的 connection-pool release path；完成的标准是，重复使用时，在连接返回 pool 之前不再累积 error listener。