test: Revert back to 3.8.0 (#834)

Author: NickLarsenNZ

tests/test-definition.yaml

@@ -8,7 +8,7 @@ dimensions:
     values:
       - 3.7.1
       - 3.7.2
-      - 3.8.1
+      - 3.8.0
       - 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.