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:postgresql` 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](testcontainers/testcontainers-java@1.20.6...1.21.0)

Updates `org.testcontainers:mongodb` 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](testcontainers/testcontainers-java@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](testcontainers/testcontainers-java@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](testcontainers/testcontainers-java@1.20.6...1.21.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

integration/pom.xml

@@ -15,7 +15,7 @@
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <testcontainers.version>1.20.6</testcontainers.version>
+        <testcontainers.version>1.21.0</testcontainers.version>
         <wiremock-jre8-standalone.version>2.35.2</wiremock-jre8-standalone.version>
     </properties>