Bump github.com/apple/swift-nio from 2.90.0 to 2.91.0

Bumps [github.com/apple/swift-nio](https://github.com/apple/swift-nio) from 2.90.0 to 2.91.0.
- [Release notes](https://github.com/apple/swift-nio/releases)
- [Commits](apple/swift-nio@2.90.0...2.91.0)

---
updated-dependencies:
- dependency-name: github.com/apple/swift-nio
  dependency-version: 2.91.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]