Add migration to sync ScanResultPolicyRead

What does this MR do and why?

Security policies are stored as YAML files in the security policy project. This required to read from git whenever we need data from a security policy. We now also store this data in the scan_result_policies table. To sync existing polices to the table, the migration in this MR kicks off sync jobs for all security policy configurations.

There are about 9000 records for which we'll queue the sync job. For self-managed, we can expect this number to be lower.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #416261 (closed)