test: Bump hdfs to 3.4.2 (#691)

Note: This was missed in stackabletech/docker-images#1374

Author: NickLarsenNZ

tests/test-definition.yaml

@@ -38,7 +38,7 @@ dimensions:
       - 4.2.0
   - name: hdfs-latest
     values:
-      - 3.4.1
+      - 3.4.2
   - name: zookeeper-latest
     values:
       - 3.9.4