Deprecate scan_result_policy_reads and use approval_policy_rules

Why are we doing this work

After we start using the read model to create approval rules (&9971 (closed)), we longer need to rely on scan_result_policy_reads as it can be replaced by approval_policy_rules and security_policies.

Relevant links

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

Verification steps