refactor: Simplify CI workflow by removing redundant virtual environment caching steps

Author: shima004

.github/workflows/ci.yaml

@@ -11,32 +11,19 @@ on:
       - develop
 
 jobs:
+  # これ以降のジョブでキャッシュが使えるようにする
   setup:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up Python
+      - &setup-python
+        name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: 3.12
-
-      - name: Cache virtual environment
-        uses: actions/cache@v4
-        with:
-          path: .venv
-          key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-venv-
-
-      - name: Install dependencies
-        run: |
-          python -m venv .venv
-          source .venv/bin/activate
-          pip install --upgrade pip
-          pip install poetry
-          poetry install
+          cache: 'poetry'
 
   ruff-format:
     needs: setup
@@ -45,23 +32,13 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Restore virtual environment cache
-        uses: actions/cache@v4
-        with:
-          path: .venv
-          key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-venv-
+      - *setup-python
 
       - name: Check ruff version
-        run: |
-          source .venv/bin/activate
-          poetry run ruff --version
+        run: poetry run ruff --version
 
       - name: Run ruff format check
-        run: |
-          source .venv/bin/activate
-          poetry run ruff format --check .
+        run: poetry run ruff format --check .
 
   ruff-lint:
     needs: setup
@@ -70,26 +47,13 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Restore virtual environment cache
-        uses: actions/cache@v4
-        with:
-          path: .venv
-          key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-venv-
-
-      - name: Set up Python environment
-        run: source .venv/bin/activate
+      - *setup-python
 
       - name: Check ruff version
-        run: |
-          source .venv/bin/activate
-          poetry run ruff --version
+        run: poetry run ruff --version
 
       - name: Run ruff lint
-        run: |
-          source .venv/bin/activate
-          poetry run ruff check --output-format=github .
+        run: poetry run ruff check --output-format=github .
 
   mypy-type-check:
     needs: setup
@@ -98,23 +62,13 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Restore virtual environment cache
-        uses: actions/cache@v4
-        with:
-          path: .venv
-          key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-venv-
+      - *setup-python
 
       - name: Check mypy version
-        run: |
-          source .venv/bin/activate
-          poetry run mypy --version
+        run: poetry run mypy --version
 
       - name: Run mypy type check
-        run: |
-          source .venv/bin/activate
-          poetry run mypy .
+        run: poetry run mypy .
 
   pytest:
     needs: setup
@@ -123,13 +77,7 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Restore virtual environment cache
-        uses: actions/cache@v4
-        with:
-          path: .venv
-          key: ${{ runner.os }}-venv-${{ hashFiles('**/poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-venv-
+      - *setup-python
 
       - name: Run pytest
         run: |