diffoscope 278 released

The diffoscope maintainers are pleased to announce the release of diffoscope version 278. This version includes the following changes:

[ Chris Lamb ]
* Temporarily remove procyon-decompiler from Build-Depends as it was removed
  from testing (#1057532). (Closes: #1082636)
* Add a helpful contextual message to the output if comparing Debian .orig
  tarballs within .dsc files without the ability to "fuzzy-match" away the
  leading directory. (Closes: reproducible-builds/diffoscope#386)
* Correctly invert "X% similar" value and do not emit "100% similar".
  (Closes: reproducible-builds/diffoscope#391)
* Update copyright years.