Bump symfony/polyfill-iconv from 1.33.0 to 1.34.0

Bumps [symfony/polyfill-iconv](https://github.com/symfony/polyfill-iconv) from 1.33.0 to 1.34.0.
- [Release notes](https://github.com/symfony/polyfill-iconv/releases)
- [Commits](symfony/polyfill-iconv@v1.33.0...v1.34.0)

---
updated-dependencies:
- dependency-name: symfony/polyfill-iconv
  dependency-version: 1.34.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]