Drop Python 3.7 from CI, add Python 3.12

Author: srittau

.github/workflows/test-and-lint.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
       fail-fast: false
 
     steps:
@@ -23,7 +23,6 @@ jobs:
       - name: Install Python packages
         run: poetry install
       - name: Lint with flake8
-        if: matrix.python-version >= 3.8
         run: |
           poetry run flake8 --version
           poetry run poe lint --show-source --statistics