Bump testcontainers.version from 1.20.6 to 1.21.0

Bumps `testcontainers.version` from 1.20.6 to 1.21.0.

Updates `org.testcontainers:junit-jupiter` from 1.20.6 to 1.21.0
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](https://github.com/testcontainers/testcontainers-java/compare/1.20.6...1.21.0)

Updates `org.testcontainers:testcontainers` from 1.20.6 to 1.21.0
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](https://github.com/testcontainers/testcontainers-java/compare/1.20.6...1.21.0

)

---
updated-dependencies:
- dependency-name: org.testcontainers:junit-jupiter
  dependency-version: 1.21.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
- dependency-name: org.testcontainers:testcontainers
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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