Render pipelines without DOMContentLoaded

What does this MR do?

Render pipelines without DOMContentLoaded

This change removes the callback on DOMContentLoaded to render the pipelines and instead renders them immediately.

It also improves the code by making the init function more consistent with the rest of the codebase. In initial tests on my browser it seems to speed up the rendering of the pipelines list.

Related to #285125 (closed)

Screenshots (strongly suggested)

LCP was slightly better in most cases on my browser:

before (4+ secs)	after (<4 secs)

Sample page can be reached by selecting project and Pipelines: http://gdk.test:3000/root/my-ci-variables/-/pipelines?page=1&scope=all

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