chore: package.json でのみ pnpm version を指定する

Author: ysk8hori

.github/workflows/integration-testing.yml

@@ -19,8 +19,6 @@ jobs:
       - uses: actions/checkout@v5
       - name: Install pnpm
         uses: pnpm/action-setup@v4
-        with:
-          version: 10
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v5
         with: