Update copyright years.

diffoscope/comparators/apk.py

diffoscope/comparators/deb.py

diffoscope/comparators/decompile.py

diffoscope/comparators/device.py

diffoscope/comparators/json.py

diffoscope/comparators/lzip.py

diffoscope/comparators/macho.py

diffoscope/comparators/missing_file.py

diffoscope/comparators/rpm_fallback.py

diffoscope/comparators/symlink.py

diffoscope/comparators/xml.py

diffoscope/external_tools.py

diffoscope/path.py

diffoscope/presenters/formats.py

diffoscope/presenters/utils.py

diffoscope/progress.py

diffoscope/tools.py