Window sizes seem unintentionally linked during resizing

Describe the bug When opening multiple books, the window sizes seem unintentionally linked whenever I try to resize any of the windows:

While this may not matter to the average reader, it can matter for editors, librarians, people studying literature, etc. who may want to view works side by side without having the excerpts be awkwardly linked in size like this. (Since this prevents people from e.g. having a small excerpt to the left and then a larger one on the right, and other such situations that might be common when doing advanced work with multiple texts.)

To Reproduce Steps to reproduce the behavior:

1. Open up two books in Foliate
2. Resize one of the windows, observe that the other one resizes too

Expected behavior Only one window should resize if I resize one of two Foliate windows.

Screenshots See demonstration above!

Version:

• Foliate version: 3.3.0
• OS/Distribution and version: Alpine Linux
• Desktop environment: KDE
• Installation method: apk via https://pkgs.alpinelinux.org/package/edge/community/x86_64/foliate

Additional context