fix: set git identity in sync-cli-docs workflow

[eskp]

Summary

• The sync-cli-docs workflow checks out the KeeperHub repo fresh, which has no git config
• git commit fails with Author identity unknown on every run
• Adds git config user.name/email for github-actions[bot] before the commit step

Test plan

• Merge and trigger workflow via workflow_dispatch or next release
• Verify the workflow completes successfully