install yarn in CI/CD

Yarn is missing from the python:2.7.18-buster base image we switched to

Author: jkasten2

.github/workflows/cd.yml

@@ -19,6 +19,8 @@ jobs:
         uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
+      - name: Install Yarn
+        run: npm install -g yarn
       - name: "[Setup] Install dependencies"
         run: yarn
       - name: "[Test] Run all tests"

.github/workflows/ci.yml

@@ -20,6 +20,8 @@ jobs:
         uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
+      - name: Install Yarn
+        run: npm install -g yarn
       - name: "[Setup] Install dependencies"
         run: yarn
       - name: "[Test] Run linters"