Add a new ci-tox.yaml workflow to run CI using tox and tox-gh.

This workflow is an alternative to `check-test-build.yaml` and is
configured to run CI through tox and tox-gh.

The actual CI workflow should be configured in the tox-gh config
(e.g., `pyproject.toml`).

Author: glenn20

.github/workflows/ci-tox.yaml

@@ -0,0 +1,61 @@
+name: CI using tox
+
+#   A reusable github workflow to run CI through tox and tox-gh:
+#   The CI workflow is configured in the tox-gh config (eg. pyproject.toml).
+#   See https://github.com/tox-dev/tox-gh.
+#
+#   Accepts the following inputs:
+#   - `os`: A json string containing the list of operating systems on which to
+#     run tests. Default is `["ubuntu-latest", "windows-latest",
+#     "macos-latest"]`.
+#   - `python-version`: A json string containing the list of python versions on
+#     which to run tests. Default is `["3.9", "3.10", "3.11", "3.12", "3.13"]`.
+#
+#   Assumes the configurations for all tools (`mypy`, `uv`, `ruff`, `pytest`,
+#   ...) are fully specified in config files (eg `pyproject.toml`).
+#
+#   Uses `uv run tox` to run the checks and tests.
+
+on:
+  workflow_call:
+    inputs:
+      os:
+        description: >-
+          A json string containing the list of operating systems on which to
+          run the test matrix.
+        default: '["ubuntu-latest", "windows-latest", "macos-latest"]'
+        type: string
+        required: false
+      python-version:
+        description: >-
+          A json string containing the list of python versions on
+          which to run the test matrix.
+        default: '["3.9", "3.10", "3.11", "3.12", "3.13"]'
+        type: string
+        required: false
+
+jobs:
+  tests:
+    name: ci-tox py${{ matrix.python-version }}-${{ matrix.os }}
+    strategy:
+      matrix:
+        os: ${{ fromJson(inputs.os) }}
+        python-version: ${{ fromJson(inputs.python-version) }}
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Checkout and setup python environment ${{ matrix.python-version }}
+        uses: glenn20/python-ci/setup@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Setup tests  # Setup the tox environment for the tests
+        run: uv run --frozen tox run -vv --notest --skip-missing-interpreters false
+
+      - name: Run tests  # Use `tox` to run the tests
+        run: uv run --frozen tox run --skip-pkg-install
+
+  build:
+    name: Build
+    uses: glenn20/python-ci/.github/workflows/build.yaml@v1