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

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

setup.cfg

diff --git a/setup.cfg b/setup.cfg
index a5ad401..890d629 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -17,6 +17,7 @@
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy