Bump symfony/polyfill-mbstring from 1.38.1 to 1.38.2

Bumps [symfony/polyfill-mbstring](https://github.com/symfony/polyfill-mbstring) from 1.38.1 to 1.38.2.
- [Release notes](https://github.com/symfony/polyfill-mbstring/releases)
- [Commits](symfony/polyfill-mbstring@v1.38.1...v1.38.2)

---
updated-dependencies:
- dependency-name: symfony/polyfill-mbstring
  dependency-version: 1.38.2
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]