Upgrade black, flake8, and pytype (#1149)

Author: seratch

.github/workflows/pytype.yml

@@ -24,7 +24,7 @@ jobs:
         pip install -e ".[testing]"
         pip install -e ".[optional]"
         # As pytype can change its behavior in newer versions, we manually upgrade it
-        pip install "pytype==2021.11.18"
+        pip install "pytype==2021.12.8"
     - name: Run pytype
       run: |
         pytype slack_sdk/

setup.py

@@ -24,8 +24,8 @@
     "Werkzeug<2",  # TODO: Flask-Sockets is not yet compatible with Flask 2.x
     "pytest-cov>=2,<3",
     "codecov>=2,<3",
-    "flake8>=3,<4",
-    "black==21.9b0",
+    "flake8>=4,<5",
+    "black==21.12b0",
     "psutil>=5,<6",
     "databases>=0.3",
     # used only under slack_sdk/*_store
@@ -34,7 +34,7 @@
     "moto<2",  # For AWS tests
 ]
 codegen_dependencies = [
-    "black==21.11b1",
+    "black==21.12b0",
 ]
 
 needs_pytest = {"pytest", "test", "ptr"}.intersection(sys.argv)