fix(dev): remove process listeners on server close, fix #2616

[patak-dev]

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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Description

See #2616
Signal event handlers are not removed during server.close(), causing a memory leak

This happens because the server is restarted (closed and recreated) any time there is a change in the config file.

Additional context

This PR also removes the listener from process.stdin 'end', which could also cause a memory leak but was not reported in the original issue.

[patak-dev]

@shigma it would be great if you could review that this PR works as you expect for your use case. Thanks!

[shigma]

@matias-capeletto Thanks for your quick response! It looks good to me.