chore(maker): update maker version policy for 0.0.21-beta.4

[taptap-cps-bot]

Updates config/maker-version-policy.json after publishing
@taptap/maker@0.0.21-beta.4 with npm tag
beta.

The workflow only updates latest or latest_beta plus updated_at.
Manual policy fields such as minimum_supported, blacklist, and message
are preserved for review-driven changes.

[greptile-apps]

Greptile Summary

This PR updates the Maker version policy for the new beta release. The main changes are:

• latest_beta now points to 0.0.21-beta.4.
• updated_at is refreshed for the policy update.
• Manual policy fields such as minimum_supported, blacklist, and message remain unchanged.

Confidence Score: 5/5

Safe to merge; the change is limited to the Maker version policy metadata.

Only the expected beta version pointer and timestamp changed, while manual policy fields remain preserved.

T-Rex Logs

What T-Rex did

• I compared the pre-change policy state and confirmed the baseline values for latest_beta, latest, minimum_supported, blacklist, message, and updated_at.
• I compared the post-change policy state and confirmed the head latest_beta moved to 0.0.21-beta.4 while latest remained 0.0.20, minimum_supported remained 0.0.1, blacklist remained [], message remained unchanged, and updated_at updated to 2026-06-26T11:17:01.424Z.
• I ran the final comparison checks and saw the command exited with code 0 and all contract checks printed True.

_{Ran code and verified through T-Rex}

_{Reviews (1): Last reviewed commit: "chore(maker): update maker version polic..." | Re-trigger Greptile}