[Issue] add additional allowed attribute

[m2-assistant]

This issue is automatically created based on existing pull request: #885: add additional allowed attribute

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data-background-lazy-load is automatically added in pagebuilder for a text element, but is not allowed and leads to a warning message when saving e.g. an attribute text, therefore whitelist this additional attribute

Description (*)

Story

Bug

Task

Fixed Issues (if relevant)

1. magento/magento2-page-builder#<issue_number>: Issue title

Builds

Related Pull Requests

Manual testing scenarios (*)

1. ...
2. ...

Questions or comments

Checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• README.md files for modified modules are updated and included in the pull request if any README.md predefined sections require an update
• All automated tests passed successfully (all builds are green)