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](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)

---
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
...

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

Author: dependabot[bot]

pom.xml

@@ -138,7 +138,7 @@
     <skipDocker>false</skipDocker>
     <sortpom-maven-plugin.version>4.0.0</sortpom-maven-plugin.version>
     <spring-boot.version>3.4.5</spring-boot.version>
-    <testcontainers.version>1.20.6</testcontainers.version>
+    <testcontainers.version>1.21.0</testcontainers.version>
     <testng.version>7.11.0</testng.version>
     <xmlunit-assertj3.version>2.10.0</xmlunit-assertj3.version>
   </properties>