chore(deps): freeze lockfile on Github Actions (#6570)

.github/workflows/lint.yml

@@ -28,7 +28,7 @@ jobs:
 
       # ESLint and Prettier must be in `package.json`
       - name: Install Node.js dependencies
-        run: yarn
+        run: yarn --frozen-lockfile
 
       - name: Run linters
         uses: wearerequired/lint-action@v1

.github/workflows/test-client.yaml

@@ -6,6 +6,6 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install modules
-        run: yarn
+        run: yarn --frozen-lockfile
       - name: Run tests
         run: yarn test:client