fix: don't crash if GitHub API call for rulesetId option fails

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing open issue: fixes 🐛 Bug: Crashes in setup mode for non-existing ruleset_id fetch #1952
• That issue was marked as status: accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

A nice exercise of the input testers.

🎁

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.43%. Comparing base (d2fc614) to head (64ffab6).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1953   +/-   ##
=======================================
  Coverage   95.42%   95.43%           
=======================================
  Files          87       87           
  Lines        3586     3590    +4     
  Branches      205      207    +2     
=======================================
+ Hits         3422     3426    +4     
  Misses        164      164           

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