Merge pull request #796 from Aiven-Open/dependabot/gradle/testcontainersVersion-1.21.4

chore(deps): bump testcontainersVersion from 1.21.1 to 1.21.4

Author: AnatolyPopov

build.gradle

@@ -133,7 +133,7 @@ subprojects {
 
         azureSdkVersion = "1.3.3"
 
-        testcontainersVersion = "1.21.1"
+        testcontainersVersion = "1.21.4"
 
         testcontainersFakeGcsServerVersion = "0.2.0"