fix(websockets): Prevent HTTP server early close in Socket.IO shutdown

[sapenlei]

fixes #13910

PR Checklist

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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Issue Number: #13910

What is the new behavior?

When ws connections and other long-running connections are handled by the same HTTP server instance, the shutdown process will not be blocked, allowing for proper termination of all connection types.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[coveralls]

Pull Request Test Coverage Report for Build 1f935bcf-2e20-49d2-8b77-6a4688c12cf5

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 91.989%

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Totals
Change from base Build 118b06bc-2db5-429c-9b45-ae989ad7db1e:	0.0%
Covered Lines:	6809
Relevant Lines:	7402

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💛 - Coveralls