Bump org.testcontainers:testcontainers from 1.21.0 to 1.21.3 (#357)

Author: dependabot[bot]

pom.xml

@@ -164,7 +164,7 @@
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>testcontainers</artifactId>
-            <version>1.21.0</version>
+            <version>1.21.3</version>
             <scope>test</scope>
         </dependency>
         <!-- Required because git plugin optionally depends on a recent version of matrix-project, and if we do not depend