Expanded Async Css Loading

[jasperf]

This PR expands the async CSS loading implementation to include additional third-party and theme stylesheets beyond the initial WooCommerce focus. The changes modify the stylesheet loading filter in app/filters.php to apply media="print" and onload attributes to a broader set of CSS files, enabling non-blocking stylesheet loading for improved page performance. This builds upon the previous async CSS loading work introduced in the codebase, extending the optimization pattern to cover more render-blocking resources.

Performance Optimization:

• Extended async loading pattern to additional stylesheets by expanding the filter logic that converts blocking CSS to non-render-blocking resources
• Stylesheets now load with media="print" initially and switch to media="all" via JavaScript onload handler, preventing CSS from blocking initial page render

Documentation:

• Updated CHANGELOG.md to document the expanded async CSS loading functionality
• Incremented theme version in style.css to reflect the enhancement

Files Changed:

• CHANGELOG.md (Modified)
• app/filters.php (Modified)
• style.css (Modified)