[2.5.5] [Contao 4.4.26] No Image in PDF Documents - tcpdf Version 6.2.25

[Ainschy]

When isotope creates a pdf document, relative image paths become absolute.
https://github.com/isotope/core/blob/master/system/modules/isotope/library/Isotope/Model/Document/Standard.php#L181-L188

In the bugfix version of TCPDF 6.2.25 the image path is checked and new replaced if necessary. In tcpdf https://github.com/tecnickcom/TCPDF/blob/master/tcpdf.php#L18819-L18850

https://github.com/tecnickcom/TCPDF/blob/master/tcpdf.php#L18831 check tcpdf the document part in the imgsrc-part, but under contao 4 we have document-root in web folder. So the check failed and tcpdf generate a wrong imgsrc path.

Set a confict rule in my composer.json for the 6.2.25 but its not the solution for this.

Contao give relative path by rendering a pdf from frontend.