What does this PR do?

Enables the PBAC (Permission-Based Access Control) feature flag globally via a database migration. This updates the Feature table to set enabled = true for the 'pbac' slug.

The PBAC feature was previously added with enabled: false in migration 20250521070158_add_pbac_feature_flags. This migration enables it for all instances.

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A - no documentation changes needed.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

1. Run the migration: yarn workspace @calcom/prisma db-migrate
2. Verify the feature flag is enabled:

   SELECT * FROM "Feature" WHERE slug = 'pbac';

   Should show enabled = true
3. Monitor e2e tests for any PBAC-related failures after enabling

Human Review Checklist

• Confirm enabling PBAC globally is the intended behavior
• Verify all PBAC-related code paths work correctly with the feature enabled
• Check if there are any known edge cases or issues when PBAC is enabled globally
• Ensure monitoring is in place for post-deployment

Checklist

• I have read the contributing guide
• My code follows the style guidelines of this project
• I have checked if my changes generate no new warnings
• My PR is appropriately sized (4 lines changed)

Link to Devin run: https://app.devin.ai/sessions/efe54642f0d44c5e9b1413c9fdee7485
Requested by: @sean-brydon