fix(update): don't log pip's output from the health check's reinstall

pip can echo a private index URL with embedded credentials;
permission_utils redacts it, the stdlib-only verifier cannot, so it
logs the exit code only.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/utils/auto_update_verify.py

@@ -214,7 +214,8 @@ class Verifier:
             # Only a refused command line is worth the next candidate. A pip
             # that ran and failed, or timed out, would just do it again.
             if not any(phrase in (result.stderr or '') for phrase in SUDO_REFUSAL_PHRASES):
-                self.log(f'reinstalling {rel} failed: {(result.stderr or "").strip()[-300:]}')
+                # Not pip's output: it can echo an index URL's credentials.
+                self.log(f'reinstalling {rel} failed (exit {result.returncode})')
                 return False
         return False