QA: Change CI value to something that can be masked

What does this MR do?

The current value cannot be masked[1] but CI variables default to masked. Rather than implementing a toggle for the masking control, simply change the value to something that can be masked.

[1] Currently, "simple" values can be masked:

• it should be a single line
• it should not have escape characters
• it should not use variables
• it should not have any whitespace
• it should be longer than 8 characters

See !25476 (merged) and gitlab-org/release/tasks#731 (comment 158629682)

Does this MR meet the acceptance criteria?

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