ci: fixes

- update artifact action
- test on more modern pythons
- unhook poetry required version

.github/workflows/ci.yaml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu, windows, macos]
-        python: ['3.8', '3.9', '3.10']
+        python: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@v2.3.4
@@ -33,7 +33,7 @@ jobs:
       - name: Run tests and ensure 100% line coverage
         run: poetry run pytest --cov-fail-under=100 --cov hpke tests
       - name: Upload coverage artifact
-        uses: actions/upload-artifact@v2.2.4
+        uses: actions/upload-artifact@v4
         with:
           name: coverage-${{ matrix.python }}-${{ matrix.os }}
           path: .coverage

pyproject.toml

@@ -20,5 +20,5 @@ black = "^22.3.0"
 mypy = "^0.942"
 
 [build-system]
-requires = ["poetry-core>=1.0.0"]
+requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"