Sync issuable state_id with null values

What does this MR do?

Sync remaining issues and merge_requests records that have state_id as nil on database.

Some of the background migrations scheduled to sync the values did timeout. For more information check: https://gitlab.com/gitlab-org/gitlab-ee/issues/26823#note_215639637

Migration output

https://gitlab.com/gitlab-org/gitlab/snippets/1894738

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Performance and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team