Remove unncessary PEP 263 encoding lines (see PEP 3120)

diffoscope/__init__.py

diffoscope/changes.py

diffoscope/comparators/__init__.py

diffoscope/comparators/android.py

diffoscope/comparators/apk.py

diffoscope/comparators/ar.py

diffoscope/comparators/berkeley_db.py

diffoscope/comparators/binary.py

diffoscope/comparators/binwalk.py

diffoscope/comparators/bzip2.py

diffoscope/comparators/cbfs.py

diffoscope/comparators/cpio.py

diffoscope/comparators/deb.py

diffoscope/comparators/debian.py

diffoscope/comparators/debian_fallback.py

diffoscope/comparators/decompile.py

diffoscope/comparators/device.py

diffoscope/comparators/dex.py

diffoscope/comparators/directory.py

diffoscope/comparators/docx.py