Bump org.testcontainers:testcontainers-bom from 1.20.6 to 1.21.0

Bumps [org.testcontainers:testcontainers-bom](https://github.com/testcontainers/testcontainers-java) 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:testcontainers-bom
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -12,7 +12,7 @@ springDependencyManagement = "1.1.7"
 springboot = "3.4.4"
 springdoc = "2.8.6"
 swagger = "7.12.0"
-testcontainers = "1.20.6"
+testcontainers = "1.21.0"
 
 [libraries]