Use yarn to install dependencies

`reviewdoc-action-prettier` is automatically running npm, but we use Yarn, which handles unmet dependencies differently. Let's make it consistent.

This caused the linter to fail when it didn't need to (https://github.com/openfoodfoundation/openfoodnetwork/pull/10300#issuecomment-1413004039).

.github/workflows/linters.yml

@@ -24,6 +24,14 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v3
+
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+
+      - name: Install JS dependencies
+        run: yarn install --frozen-lockfile
+
       - name: prettier
         uses: EPMatt/reviewdog-action-prettier@v1
         with: