chore: Switch from yarn to pnpm

.github/workflows/tests.yml

@@ -20,28 +20,31 @@ jobs:
         uses: actions/checkout@v4
 
       - uses: actions/cache@v4
-        id: yarn-and-build-cache
+        id: pnpm-and-build-cache
         with:
           path: |
             ~/.cache/Cypress
             build
             node_modules
-          key: ${{ runner.os }}-node_modules-build-${{ hashFiles('**/yarn.lock') }}
+          key: ${{ runner.os }}-node_modules-build-${{ hashFiles('**/pnpm-lock.yaml') }}
           restore-keys: |
             ${{ runner.os }}-node_modules-build-
 
       - uses: actions/setup-node@v4
         with:
           node-version-file: '.node-version'
-          cache: 'yarn'
+          cache: 'pnpm'
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v3
 
       # Install NPM dependencies, cache them correctly
       # and run all Cypress tests
       - name: Cypress run
         uses: cypress-io/github-action@v6
         with:
-          build: yarn build
-          start: yarn preview
+          build: pnpm build
+          start: pnpm preview
           wait-on: 'http://localhost:3000'
           record: true
           parallel: true