Add custom action for setting up Poetry

.github/actions/setup-poetry/action.yml

@@ -0,0 +1,24 @@
+name: "Set up Poetry"
+description: "Sets up Python and Poetry"
+
+inputs:
+  python-version:
+    required: false
+    description: "Version of Python to use"
+    default: "3.13"
+  poetry-version:
+    required: false
+    description: "Version of Poetry to use"
+    default: "2.1.0"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install Poetry
+      run: pipx install poetry==${{ inputs.poetry-version }}
+      shell: bash
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ inputs.python-version }}
+        cache: "poetry"

.github/workflows/lint.yml

@@ -18,13 +18,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install Poetry
-        run: pipx install poetry==${{ env.DEFAULT_POETRY_VERSION }}
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
-          cache: "poetry"
+      - name: Set up Poetry
+        uses: ./.github/actions/setup-poetry
       - name: Install dependencies
         run: poetry install --with dev
       - name: Lint
@@ -34,13 +29,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Install Poetry
-        run: pipx install poetry==${{ env.DEFAULT_POETRY_VERSION }}
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
-          cache: "poetry"
+      - name: Set up Poetry
+        uses: ./.github/actions/setup-poetry
       - name: Install dependencies
         run: poetry install --with dev
       - name: Lint

.github/workflows/test.yml

@@ -25,13 +25,10 @@ jobs:
       fail-fast: false
     steps:
       - uses: actions/checkout@v4
-      - name: Install Poetry
-        run: pipx install poetry==${{ env.DEFAULT_POETRY_VERSION }}
-      - name: Set up Python
-        uses: actions/setup-python@v5
+      - name: Set up Poetry
+        uses: ./.github/actions/setup-poetry
         with:
           python-version: ${{ matrix.python-version }}
-          cache: "poetry"
       - name: Install dependencies
         run: poetry install --with dev
       - name: Test