Fix f-string

gvanrossum · kumaraditya303 · web-flow · commit a73c227473cf · 2023-01-05T12:54:06.000-08:00
Co-authored-by: Kumar Aditya &lt;59607654+kumaraditya303@users.noreply.github.com&gt;
diff --git a/Tools/cases_generator/test_generator.py b/Tools/cases_generator/test_generator.py
@@ -17,7 +17,7 @@ def run_test(input: str, expected: str):
     a.parse()
     a.analyze()
     if a.errors:
-        raise RuntimeError("Found {a.errors} errors")
+        raise RuntimeError(f"Found {a.errors} errors")
     a.write_instructions()
     temp_output.seek(0)
     lines = temp_output.readlines()
