Bump multidict from 6.5.1 to 6.6.3

Bumps [multidict](https://github.com/aio-libs/multidict) from 6.5.1 to 6.6.3.
- [Release notes](https://github.com/aio-libs/multidict/releases)
- [Changelog](https://github.com/aio-libs/multidict/blob/master/CHANGES.rst)
- [Commits](aio-libs/multidict@v6.5.1...v6.6.3)

---
updated-dependencies:
- dependency-name: multidict
  dependency-version: 6.6.3
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]