Compatibility issue with PHP 8.3

Fetch/Attachment Dynamic property allocation.

[tedivm]

Can you be more specific- like a full error message and stack trace?

Here is the error message.

Deprecated Functionality: Creation of dynamic property Fetch\Attachment::$mimeType is deprecated in vendor/tedivm/fetch/src/Fetch/Attachment.php on line 103

"mimeType" and "encoding" properties are not defined.