v0.13.0.1

This patch release fixes compatibility with Composer-based WordPress installations, and a few minor issues introduced in the previous release.

• fix: Check if classes are loaded by a different autoloader before attempting to autoload them. H/t @cvanh
• fix: Return wp_max_upload_size() instead of null if GfFieldWithFileSizeSetting.maxFileSize is null. H/t @Gytjarek
• fix: Fix typo in Autoloader release URL.
• fix: Ensure a valid source ID exists before attempting to resolve a connectedFormField.
• ci: Test compatibility against WP 6.6.
• ci: Replace calls to docker-compose with docker compose.

Full Changelog: v0.13.0...v0.13.0.1