Feat: WordPress 6.5.4 Compatibility

[nateconley]

Description of the Change

• Ensures compatibility with WordPress 6.5.4
• Remove compatibility with Wordpress < 6.1.1 (6.1.1 released 11/15/2022)
• Removes broken jQuery scrollTo library in favor of window.scrollTo. See options.behavior support: https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollTo#browser_compatibility
• Removes WordPress polyfills for core functions < 2.8.0

Important Note: Known deprecation warnings will be thrown for WordPress 6.1.1 and newer PHP versions:

PHP Deprecated: Return type of Requests_Cookie_Jar::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

PHP Deprecated: Calling get_class() without arguments is deprecated

Testing WordPress 6.1.1 with PHP 8.0 will not display these deprecations.

Closes #1

How to test the Change

Environments

• WordPress core version 6.5.4
• WordPress core version 6.1.1
• Theme Twenty Twenty-Four
• Theme Twenty Twenty-One

Acceptance

• Shortcode [mailchimpsf_widget] works as expected
• Widget works as expected

Changelog Entry

Added - compatibility to WordPress 6.5.4 Deprecated - support for WordPress < 6.1.1 Removed - polyfills for WordPress < 2.8.0 Removed - deprecated jQuery scrollTo

Credits

@nateconley

Checklist:

• [x] I agree to follow this project's Code of Conduct.
• [x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [x] All new and existing tests pass.