Unpack sandbox result instead of nesting quotes in f-string

Ruff and the CMS preflight disagreed on quote style for the nested
f-string in compare.py. Unpacking the result avoids nested quotes, so
the folder-level ruff.toml override is no longer needed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: realpython-bot

python-sandbox/compare.py

@@ -24,7 +24,8 @@
 
 print("3. Locked-down container:")
 result = run_untrusted(HOSTILE)
-if result["exit_code"] == 0:
-    print(result["stdout"].strip())
+exit_code, stdout, stderr = result.values()
+if exit_code == 0:
+    print(stdout.strip())
 else:
-    print(f"Sandbox failed ({result["exit_code"]}): {result["stderr"]}")
+    print(f"Sandbox failed ({exit_code}): {stderr}")