Dubliced blurred paths become "blur-linked"
#### Summary:
When duplicating a blurred path, increasing the blur on either path affects the blur of the other path. The objects are temporarily "blur-linked".
Polygon has confirmed that they were able to reproduce the issue while following the steps below.
#### Steps to reproduce:
1. Open Inkscape
2. Draw a line with the bezier pen tool
2. give it a stroke
3. give it a blur
4. duplicate the line
5. move the top line to the side
6. increase the blur of either line
#### What happened?
The other line also increases the blur.
#### What should have happened?
Only the selected line should be affected
#### Version info
```
Inkscape 1.3 (0e150ed, 2023-07-21)
GLib version: 2.64.6
GTK version: 3.24.20
glibmm version: 2.64.2
gtkmm version: 3.24.2
libxml2 version: 2.9.10
libxslt version: 1.1.34
Cairo version: 1.17.7
Pango version: 1.44.7
HarfBuzz version: 2.6.4
OS version: Manjaro Linux
```
Note: blur seems to have other bugs such as causing the line to disappear completely if the line is drawn vertically, although I cannot reliably reproduce it. Thought it possible that these issues are linked.
issue