Move reCAPTCHA to core extension
This is a tracking issue to track progress.
- https://github.com/civicrm/civicrm-core/pull/19967 - initial extension merged.
- https://github.com/civicrm/civicrm-core/pull/19999 - add recaptcha to distmaker - merged.
- https://github.com/civicrm/civicrm-core/pull/20011 - move recaptcha library to extension - merged.
- https://github.com/civicrm/civicrm-core/pull/20019 - Use standard function to add reCAPTCHA to PCPAccount form - merged.
Need to cleanup and move all calls to add reCAPTCHA to forms to the extension.