test: Correct the versions to test against (#825)

* test: Correct the versions to test against

* test: Set upgrade test to lowest and highest versions

Author: NickLarsenNZ

tests/test-definition.yaml

@@ -6,8 +6,9 @@
 dimensions:
   - name: kafka
     values:
+      - 3.7.1
       - 3.7.2
-      - 3.8.0
+      - 3.8.1
       - 3.9.0
       # Alternatively, if you want to use a custom image, append a comma and the full image name to the product version
       # as in the example below.
@@ -26,7 +27,7 @@ dimensions:
       - 3.9.2
   - name: upgrade_old
     values:
-      - 3.8.0
+      - 3.7.1
   - name: upgrade_new
     values:
       - 3.9.0