Clean up js-* classes from pipeline_url.vue

What does this MR do?

For issue #225669 (closed).

This is a cleanup of the js-* classes in pipeline_url.vue.

data-testid selectors have already been implemented in the component in a previous commit (b28833cc), so this is just a cleanup of unnecessary classes and E2E tests that use them as selectors.

Screenshots

pipeline_url.vue manages the Pipeline column in the CI table. It contains a link to the pipeline and labels about the status of the pipeline. Since this is just a cleanup, there should be no visual or functional changes to the UI.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• 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
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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