[keyserver] Regenerate permissions for all threads

Summary:
We need this migration to apply the changes from earlier in the stack.

Depends on D13075

Test Plan:
I tested this in combination with the previous diff:

• Create a community
• Update Members permission to include managing tags
• Run the migration
• Confirm that the managing tags permissions is still present

Reviewers: tomek, inka

Reviewed By: tomek

Differential Revision: https://phab.comm.dev/D13076