Fix: CI の実装ミスを修正

Windows では taskipy 管理の開発コマンドは動作しないことを失念していた…

.github/workflows/ci.yml

@@ -45,11 +45,12 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip taskipy
-        task install
+        python -m pip install --upgrade pip
+        pip uninstall -y setuptools  # <- magic!
+        pip install -e '.[dev,test]'
     - name: Lint with pysen
       run: |
-        task lint
+        pysen run lint
     - name: Test with pytest
       run: |
-        task test
+        pytest