Drop old interpreter versions from CI (#159)

.github/workflows/ci.yml

@@ -19,33 +19,17 @@ jobs:
       max-parallel: 4
       matrix:
         platform: [ ubuntu-latest, macos-latest, windows-latest ]
-        python-version: [ '3.6', '3.7', '3.8', '3.9', '3.10', '3.11', 'pypy3.8']
+        python-version: [ '3.8', '3.9', '3.10', '3.11', 'pypy3.8']
 
     steps:
       - uses: actions/checkout@v3
 
-      - name: Install Python 3.6
-        if: matrix.platform == 'ubuntu-latest' && matrix.python-version == '3.6'
-        run: |
-          sudo add-apt-repository ppa:deadsnakes/ppa
-          sudo apt-get update
-          sudo apt-get install python3.6
-
       - name: Setup Nox
-        if: matrix.platform != 'ubuntu-latest' || matrix.python-version != '3.6'
         uses: wntrblm/nox@2023.04.22
         with:
           python-versions: ${{ matrix.python-version }}
       - name: Run tests
-        if: matrix.python-version != '3.6'
-        run: |
-          nox -s tests-${{ matrix.python-version }}
-        env:
-          PLATFORM: ${{ matrix.platform }}
-      - name: Run tests ubuntu 3.6
-        if: matrix.platform == 'ubuntu-latest' && matrix.python-version == '3.6'
         run: |
-          sudo apt-get install -y nox
           nox -s tests-${{ matrix.python-version }}
         env:
           PLATFORM: ${{ matrix.platform }}