Fix loading all issues when board list is collapsed

What does this MR do?

Fix repeated requests to fetch issues when loading a board with collapsed list containing a lot of issues.

To test in the browser:

• Load a board which has at least one list with more than 20 issues
• Collapse the list
• Reload the page
• Several issues fetch requests can be seen in the network tab before the bugfix.

Screenshots

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

Availability 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

Closes #26207 (closed)