Saving a file doesn't respect the "Append file extension automatically" checkbox.

Steps to reproduce:

• Open Inkscape
• Select "New document"
• File->Save
• In "Save" dialog, change file type to "PDF" and save.

What happened?

Saved file does not have ".pdf" as extension.

What should have happened?

Saved file should have ".pdf" as extension.

Inkscape Version and Operating System:

• Inkscape Version: 1.4.x
• Operating System: Fedora Linux