Incorrect handling of FontMatrix and transformation matrices with internal PDF import
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#### Steps to reproduce:
<!-- Describe what you did (step-by-step) so we can reproduce: -->
- open Inkscape
- import PDF with internal importer
- select to replace unknown fonts with closes installed one
#### What happened?
- text is there, but not visible
- text objects are there, but with fontsize 1e-32px according to XML editor
- text tool shows fontsize of 7.02pt though
- setting the text size manually either with the text tool or in the XML works
- more specifically, the text has the following style after importing
```css
font-variant: normal;
font-weight: normal;
font-size: 1e-32px;
font-family: 'Open Sans';
writing-mode: lr-tb;
fill: #333333;
fill-opacity: 1;
fill-rule: nonzero;
stroke: none;
```
#### What should have happened?
the PDF gets imported with the correct fontsize set
#### Inkscape Version and Operating System:
- Inkscape Version: 1.3.2 (091e20ef0f, 2023-11-25) \
**Edit:** the problem also exists on latest master (f5458ab7)
- Operating System: Fedora
- Operating System version: 39
[example.pdf](/uploads/eb0266efe63484061d283f50f64800da/original.pdf)
issue