Feature/5987 lazyload css

[CrochetFeve0251]

Description

Fix the js script and an issue with relative urls.

Fixes #5987

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality).
• Bug fix (non-breaking change which fixes an issue).
• Enhancement (non-breaking change which improves an existing functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as before).
• This change requires a documentation update.

Is the solution different from the one proposed during the grooming?

Please describe in this section if there is any change to the groomed solution, and why.

Checklists

Generic development checklist

• My code follows the style guidelines of this project, with adapted comments and without new warnings.
• I have added unit and integration tests that prove my fix is effective or that my feature works.
• The CI passes locally with my changes (including unit tests, integration tests, linter).
• Any dependent changes have been merged and published in downstream modules.
• If applicable, I have made corresponding changes to the documentation. Provide a link to the documentation.

Test summary

• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I validated all Acceptance Criteria of the related issues. (If applicable, provide proof).
• I validated all test plan the QA Review asked me to.

If not, detail what you could not test.

Please describe any additional tests you performed.

[engahmeds3ed]

As discussed with @CrochetFeve0251 this will prevent the error but we need not to add the script when DONOTCACHEPAGE constant is set not to add the script in not cached pages.