Bump webmozart/assert from 1.12.1 to 2.1.6

Bumps [webmozart/assert](https://github.com/webmozarts/assert) from 1.12.1 to 2.1.6.
- [Release notes](https://github.com/webmozarts/assert/releases)
- [Changelog](https://github.com/webmozarts/assert/blob/master/CHANGELOG.md)
- [Commits](webmozarts/assert@1.12.1...2.1.6)

---
updated-dependencies:
- dependency-name: webmozart/assert
  dependency-version: 2.1.6
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Author: dependabot[bot]