Update pre-commit dependencies.

Author: Michael Howitz

.pre-commit-config.yaml

@@ -1,12 +1,12 @@
 ---
 repos:
     - repo: https://github.com/psf/black
-      rev: 20.8b1
+      rev: 21.9b0
       hooks:
           - id: black
             args: [--safe, --quiet, --target-version, py36]
     - repo: https://github.com/pre-commit/pre-commit-hooks
-      rev: v3.4.0
+      rev: v4.0.1
       hooks:
           - id: trailing-whitespace
           - id: end-of-file-fixer
@@ -16,18 +16,18 @@ repos:
           - id: debug-statements
             language_version: python3
     - repo: https://gitlab.com/pycqa/flake8
-      rev: 3.8.4
+      rev: 3.9.2
       hooks:
           - id: flake8
             language_version: python3
             additional_dependencies: [flake8-typing-imports>=1.9.0]
     - repo: https://github.com/asottile/reorder_python_imports
-      rev: v2.3.6
+      rev: v2.6.0
       hooks:
           - id: reorder-python-imports
             args: ['--application-directories=.:src', --py3-plus]
     - repo: https://github.com/asottile/pyupgrade
-      rev: v2.7.4
+      rev: v2.26.0
       hooks:
           - id: pyupgrade
             args: [--py36-plus]