Remove SoftwareLicensePolicies without ScanResultPolicy

What does this MR do and why?

This MR adds a post_deployment_migration to removes the SoftwareLicensePolicies without ScanResultPolicy.

This cleanup is one of the steps required for removal of License-Check feature as described in #397067 (closed).

Query

DELETE FROM software_license_policies
WHERE scan_result_policy_id IS NULL

Before Index

https://postgres.ai/console/gitlab/gitlab-production-tunnel-pg12/sessions/18057/commands/59909

Migrations

up

main: == 20230501165244 RemoveSoftwareLicensePoliciesWithoutScanResultPolicyId: migrating 
main: -- execute("DELETE FROM software_license_policies WHERE scan_result_policy_id IS NULL")
main:    -> 0.0027s
main: == 20230501165244 RemoveSoftwareLicensePoliciesWithoutScanResultPolicyId: migrated (0.0053s)

down

main: == 20230501165244 RemoveSoftwareLicensePoliciesWithoutScanResultPolicyId: reverting 
main: == 20230501165244 RemoveSoftwareLicensePoliciesWithoutScanResultPolicyId: reverted (0.0101s) 

Expected number of rows affected:

SELECT COUNT(*) FROM software_license_policies WHERE scan_result_policy_id IS NULL;
 count 
-------
 26847
(1 row)

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.