CFType may attempt to call createTextNode with a null value

[andrew-pirkl]

CFType may have a null value https://github.com/TECLIB/CFPropertyList/blob/develop/src/CFPropertyList/CFType.php#L63 and attempt to call createTextNode https://github.com/TECLIB/CFPropertyList/blob/develop/src/CFPropertyList/CFType.php#L110 with that null value. This is deprecated in php 8 and throws the error:

Passing null to parameter #1 ($data) of type string is deprecated

This is related to: https://wiki.php.net/rfc/deprecate_null_to_scalar_internal_arg and should be fixed before passing null to non-nullable arguments is removed in a future php version.