Fix failed tests, linter errors, and restructure (faif#477)

* Switch development dependencies to Pipenv lockfile

- add Pipfile and Dependabot-compatible Pipfile.lock
- update lint, tox, CI, Travis, and Makefile workflows
- support Python 3.10 through 3.14
- remove the pip-tools requirements lockfile
- standardize linting, type checking, and tests

* Streamline GitHub Actions CI workflow

- consolidate duplicate lint and PR workflows
- run strict linting, type checking, and tests
- test against Python 3.10 through 3.14
- install dependencies from Pipfile.lock
- add caching, timeouts, minimal permissions, and concurrency control
- remove ignored failures and fragile changed-file logic

Author: faif

.github/dependabot.yml

@@ -0,0 +1,12 @@
+version: 2
+updates:
+  - package-ecosystem: pip
+    directory: /
+    schedule:
+      interval: weekly
+    versioning-strategy: increase-if-necessary
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly

.github/workflows/lint_pr.yml

@@ -1,36 +1,62 @@
-name: lint_python
-on: [pull_request, push]
+name: Python CI
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: python-ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  lint_python:
+  quality:
+    name: Lint, type-check, and test
     runs-on: ubuntu-24.04
+    timeout-minutes: 15
     steps:
       - uses: actions/checkout@v6
+
       - uses: actions/setup-python@v6
         with:
-          python-version: 3.12
-      - name: Install dependencies
+          python-version: "3.12"
+          cache: pip
+          cache-dependency-path: Pipfile.lock
+
+      - name: Run quality checks
+        run: ./lint.sh
+
+  tests:
+    name: Test on Python ${{ matrix.python-version }}
+    runs-on: ubuntu-24.04
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - "3.10"
+          - "3.11"
+          - "3.12"
+          - "3.13"
+          - "3.14"
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-python@v6
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: pip
+          cache-dependency-path: Pipfile.lock
+
+      - name: Install locked dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install .[dev]
-      - name: Lint with flake8
-        run: flake8 ./patterns --count --show-source --statistics
-        continue-on-error: true
-      - name: Format check with isort and black
-        run: |
-          isort --profile black --check ./patterns
-          black --check ./patterns
-        continue-on-error: true
-      - name: Type check with mypy
-        run: mypy --ignore-missing-imports ./patterns || true
-        continue-on-error: true
-      - name: Run tests with pytest
-        run: |
-          pytest ./patterns
-          pytest --doctest-modules ./patterns || true
-        continue-on-error: true
-      - name: Check Python version compatibility
-        run: shopt -s globstar && pyupgrade --py312-plus ./patterns/**/*.py
-        continue-on-error: true
-      - name: Run tox
-        run: tox
-        continue-on-error: true
+          python -m pip install pipenv
+          pipenv requirements --dev > "${RUNNER_TEMP}/requirements-dev.txt"
+          python -m pip install -r "${RUNNER_TEMP}/requirements-dev.txt"
+          python -m pip install --no-build-isolation --no-deps -e .
+
+      - name: Run tests
+        run: python -m pytest tests patterns