If a FileNotFound exception occurs, log a simple message indicating the tests may

have not run.

tools/ci/render_test_output.py

@@ -13,6 +13,7 @@ print("::group::Arguments")
 print(f"{sys.argv}") 
 print("::endgroup::")
 for xmlfile in xmlfiles:
+    try:
         tree = ET.parse(xmlfile)
     
         root = tree.getroot()
@@ -38,7 +39,9 @@ for xmlfile in xmlfiles:
             else:
                 print(f"::error file={testname}::{message} in {time}s")
                 print(child.text)
-    body = f"passed={success} failures={failures} errors={errors} skipped={skipped}"
+        body = f" passed={success} failures={failures} errors={errors} skipped={skipped}"
         print(f"::set-output name={suitename}::={body}")
+    except FileNotFoundError:
+        print(f"::error::Unable to open test results file {xmlfile} - check if the tests completed")
     print("::endgroup::")