Dropped support for Python 3.7.

setup.cfg

@@ -19,7 +19,6 @@ classifiers =
     License :: OSI Approved :: MIT License
     Operating System :: OS Independent
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
@@ -34,7 +33,7 @@ classifiers =
 packages = find:
 package_dir =
      = src
-python_requires = >=3.7,<4
+python_requires = >=3.8,<4
 
 [options.packages.find]
 where = src