Fix outstanding CI issues on the main branch

[apyrgio]

Fix the following outstanding issue on the main branch:

• A small lint issue. This will be fixed once Fix some minor lint issues #826 is merged.
• Fedora 39/40 failures, due to a stuck PySide6 dependency. This will be fixed once build: bump the minimum python version to 3.9 #818 is merged.

Also, on a semi-related note, we need to fix a build failure for PySide6 in Fedora 41, on the maint-dangerzone-pyside6 repo. This will be fixed once freedomofpress/maint-dangerzone-pyside6#9 is merged.

[apyrgio]

We have resolved al of these issues, so we can close this one as well.