Update Managed Files

[ChiaAutomation]

Note

Low Risk
Workflow-only change that reduces token scope; no application or security logic changes.

Overview
Adds an explicit permissions: contents: read block to the Check commit signing GitHub Actions workflow, matching the pattern already used in workflows like build-wheels and dependency-review.

This scopes the workflow token to read-only repository contents instead of relying on broader default GITHUB_TOKEN permissions.

^{Reviewed by Cursor Bugbot for commit dceaf24. Bugbot is set up for automated code reviews on this repo. Configure here.}