Python 3.12 throws syntax warnings regarding invalid escape sequences.
In the case of pompem the invalid escape sequences were caused by unescaped
or erroneous backslashes.

Apply hints suggested by the [multi-arch hinter](https://wiki.debian.org/MultiArch/Hints)

See merge request !1

Changes-By: lintian-brush
Fixes: lintian: out-of-date-standards-version
See-also: https://lintian.debian.org/tags/out-of-date-standards-version.html

pompem (0.2.0-3) unstable; urgency=medium

  * Updated my email address.
  * debian/control:
      - Bumped Standards-Version to 4.0.0.
      - Dropped python3.5 in Build-depends, its not necessary.
      - Updated to depend python3 instead of python3.5.
        Thanks to Jeremy Bicha <[email protected]> (Closes: #870011)
  * debian/copyright:
      - Updated the packaging copyright years.
  * debian/patches/add-shebang-line.patch:
      - Updated to add python3 instead of python3.5.