Upgrade supported Python version to 3.12 (#154)

Address #106.

.github/workflows/continuous-integration.yml

@@ -14,12 +14,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, '3.10', '3.11']
+        python-version: [3.8, 3.9, '3.10', '3.11', '3.12']
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
       - name: Upgrade pip

pyproject.toml

@@ -7,7 +7,7 @@ name            = "sympde"
 version         = "0.18.3"
 description     = "Symbolic calculus for partial differential equations (and variational forms)"
 readme          = "README.rst"
-requires-python = ">= 3.8, < 3.12"
+requires-python = ">= 3.8, < 3.13"
 license         = {file = "LICENSE"}
 authors         = [{name = "Ahmed Ratnani", email = "[email protected]"}]
 maintainers = [