build(deps): bump the test-dependencies group with 3 updates (#666)

Bumps the test-dependencies group with 3 updates: [org.testcontainers:junit-jupiter](https://github.com/testcontainers/testcontainers-java), [org.testcontainers:localstack](https://github.com/testcontainers/testcontainers-java) and [org.testcontainers:testcontainers](https://github.com/testcontainers/testcontainers-java).


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:localstack` 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:production
  update-type: version-update:semver-minor
  dependency-group: test-dependencies
- dependency-name: org.testcontainers:localstack
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: test-dependencies
- dependency-name: org.testcontainers:testcontainers
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: test-dependencies
...

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

Author: dependabot[bot]

build.gradle

@@ -131,9 +131,9 @@ testing {
         integrationTest(JvmTestSuite) {
             dependencies {
                 implementation project
-                implementation 'org.testcontainers:junit-jupiter:1.20.6'
-                implementation 'org.testcontainers:localstack:1.20.6'
-                implementation 'org.testcontainers:testcontainers:1.20.6'
+                implementation 'org.testcontainers:junit-jupiter:1.21.0'
+                implementation 'org.testcontainers:localstack:1.21.0'
+                implementation 'org.testcontainers:testcontainers:1.21.0'
             }
         }
         withType(JvmTestSuite).configureEach {