Bump Python compat target to 3.8

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
             uses: actions/setup-python@v1
             with:
                 # matches compat target in setup.py
-                python-version: '3.6'
+                python-version: '3.8'
         -   name: "Main Script"
             run: |
                 curl -L -O https://gitlab.tiker.net/inducer/ci-support/raw/main/prepare-and-run-flake8.sh
@@ -28,7 +28,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                python-version: ['3.6', '3.8', '3.x']
+                python-version: ['3.8', '3.x']
         steps:
         -   uses: actions/checkout@v2
         -

modepy/tools.py

@@ -55,11 +55,7 @@
 """
 
 from typing import Tuple, TypeVar
-try:
-    # NOTE: only available in >=3.8
-    from typing import Protocol, runtime_checkable
-except ImportError:
-    from typing_extensions import Protocol, runtime_checkable  # type: ignore[misc]
+from typing import Protocol, runtime_checkable
 
 from functools import reduce
 from math import gamma      # noqa: F401

setup.py

@@ -36,15 +36,12 @@ def main():
               ],
 
           packages=find_packages(),
-          python_requires="~=3.6",
+          python_requires="~=3.8",
           install_requires=[
               "numpy",
               "pytools>=2013.1",
               "pytest>=2.3",
               "pymbolic",
-
-              "dataclasses; python_version<'3.7'",
-              "typing_extensions; python_version<'3.8'",
               ],
           package_data={"modepy": ["py.typed"]},
           )