Bump testcontainers.version from 1.20.6 to 1.21.0 (#1322)

Bumps `testcontainers.version` from 1.20.6 to 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)

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)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -107,7 +107,7 @@
     <plexus-interactivity-api.version>1.4</plexus-interactivity-api.version>
     <roaster.version>2.30.1.Final</roaster.version>
     <takari-smart-builder.version>1.0.2</takari-smart-builder.version>
-    <testcontainers.version>1.20.6</testcontainers.version>
+    <testcontainers.version>1.21.0</testcontainers.version>
     <xstream.version>1.4.21</xstream.version>
   </properties>