Bump testContainersVersion from 1.21.3 to 1.21.4

Bumps `testContainersVersion` from 1.21.3 to 1.21.4.

Updates `org.testcontainers:junit-jupiter` from 1.21.3 to 1.21.4
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.21.3...1.21.4)

Updates `org.testcontainers:mariadb` from 1.21.3 to 1.21.4
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.21.3...1.21.4)

Updates `org.testcontainers:rabbitmq` from 1.21.3 to 1.21.4
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.21.3...1.21.4)

---
updated-dependencies:
- dependency-name: org.testcontainers:junit-jupiter
  dependency-version: 1.21.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.testcontainers:mariadb
  dependency-version: 1.21.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.testcontainers:rabbitmq
  dependency-version: 1.21.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

build.gradle

@@ -190,7 +190,7 @@ dependencies {
   runtimeOnly("org.bouncycastle:bcpkix-jdk15on:1.70")
 
   testImplementation("junit-addons:junit-addons:1.4")
-  def testContainersVersion = "1.21.3"
+  def testContainersVersion = "1.21.4"
   testImplementation("org.testcontainers:junit-jupiter:${testContainersVersion}")
   testImplementation("org.testcontainers:mariadb:${testContainersVersion}")
   testImplementation("org.testcontainers:rabbitmq:${testContainersVersion}")