chore: add cache: 'yarn'

Author: Ninfa-Jeon

.github/workflows/ci.yaml

@@ -20,6 +20,7 @@ jobs:
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
+          cache: "yarn"
       - name: Install
         run: yarn install --immutable
       - run: yarn test
@@ -36,6 +37,7 @@ jobs:
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
+          cache: "yarn"
       - name: Install
         run: yarn install --immutable
       - run: yarn prettier --check 'api/**/*'
@@ -52,6 +54,7 @@ jobs:
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
+          cache: "yarn"
       - name: Install
         run: yarn install --immutable
       - run: yarn lint
@@ -68,6 +71,7 @@ jobs:
         uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
+          cache: "yarn"
       - name: Install
         run: yarn install --immutable
       - run: CI=false yarn build