Avoid the need for nvm to be installed in the GitHub Action workflows

`nvm` no longer seems to be present when running Node in a GitHub
Action. However, the correct Node version is already extracted in
previous steps, so it's not actually needed here. Therefore, the
`script/setup` call in the 'Install dependencies' step can be simplified
to just a call to `npm install`.

.github/workflows/playwright.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           node-version: ${{ steps.nvm.outputs.NODE_VERSION }}
       - name: Install dependencies
-        run: script/setup
+        run: script/setup ci
       - name: Install Playwright Browsers
         run: npx playwright install --with-deps
       - name: Run Playwright tests

.github/workflows/test.yml

@@ -23,7 +23,7 @@ jobs:
           node-version: ${{ steps.nvm.outputs.NODE_VERSION }}
       - name: Install dependencies
         run: |
-          ./script/setup
+          ./script/setup ci
       - name: Run lint & test
         run: |
           ./script/test

script/setup

@@ -17,5 +17,8 @@ fi
 
 rm -rf node_modules
 
-script/bootstrap
-
+if [ "$1" = "ci" ]; then
+  npm install
+else
+  script/bootstrap
+fi