Fix easy-thumbnail dependencies and lint (flake8 5.0.0)

[numahell]

• Fix lint due to pythoncodestyle new version
• Fix dependencies error due to easy-thumbnail new version https://pypi.org/project/easy-thumbnails/2.8.2/

  Version 2.8.0 adds support for thumbnailing SVG images when installed with the [svg] extra.

[codecov-commenter]

Codecov Report

Merging #247 (42819a1) into master (f9584e6) will not change coverage. The diff coverage is n/a.

:exclamation: Current head 42819a1 differs from pull request most recent head 07bbc4e. Consider uploading reports for the commit 07bbc4e to get more accurate results

@@           Coverage Diff           @@
##           master     #247   +/-   ##
=======================================
  Coverage   88.50%   88.50%           
=======================================
  Files          30       30           
  Lines        2228     2228           
=======================================
  Hits         1972     1972           
  Misses        256      256           

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