Improve intermittently failing create_issue_spec smoke test

What does this MR do?

Test create_issue_spec intermittently fails in review-qa-smoke on file upload (see review-qa-smoke failure analysis issue), however this issue didn't come up on any other environments recently (see the testcase report) so it seems to be Review App specific.

This MR replaces the image file with the one that has proven to work on Review Apps (see !56449 (merged)).

Completes one of the tasks of gitlab-com/www-gitlab-com#11568 (closed).

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• [-] I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• [-] I have added/updated documentation, or it's not needed. (Is documentation required?)
• [-] I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• [-] I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• [-] This change is backwards compatible across updates, or this does not apply.