[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/psf/black: 20.8b1 → 21.4b0](psf/black@20.8b1...21.4b0)
- [github.com/asottile/reorder_python_imports: v2.4.0 → v2.5.0](asottile/reorder-python-imports@v2.4.0...v2.5.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 exclude: doc/en/example/py2py3/test_py2.py
 repos:
 -   repo: https://github.com/psf/black
-    rev: 20.8b1
+    rev: 21.4b0
     hooks:
     -   id: black
         args: [--safe, --quiet]
@@ -18,7 +18,7 @@ repos:
     -   id: fix-encoding-pragma
     -   id: check-yaml
 -   repo: https://github.com/asottile/reorder_python_imports
-    rev: v2.4.0
+    rev: v2.5.0
     hooks:
     -   id: reorder-python-imports
         args: ['--application-directories=execnet']