Upgrade flake8 to verison 7.1.1

[glenrobson]

Decisions will have to be made on new checks and if we want to implement them or ignore them. Example issue:

./iiif_prezi3/helpers/add_label.py:20:20: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/helpers/add_label.py:31:20: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/helpers/auto_fields.py:123:14: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/helpers/auto_fields.py:125:14: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/helpers/make_range.py:14:12: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/helpers/make_range.py:19:14: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/loader.py:9:23: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/loader.py:11:44: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/loader.py:36:8: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/loader.py:39:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
  ./iiif_prezi3/loader.py:47:12: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`

[glenrobson]

Yes fix: https://www.flake8rules.com/rules/E721.html