[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

setup.cfg

@@ -15,9 +15,6 @@ classifiers =
     Natural Language :: English
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.7
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
     Programming Language :: Python :: Implementation :: CPython
 project_urls =
     Tracker = https://github.com/ianhi/mpl-image-labeller/issues