Fix CI for PRs on master (#688)

This does three things:
1. it makes sure we explicitly use _our_ lerna, not the global one that seems to come with `ubuntu_latest` in the build step
2. it makes sure we use the storybook CLI that matches our storybook version when extracting the stories, `npx sb` would install the latest version if it is not already in node_modules
3. it updates chromatic because there was an issue with the chromatic part failing despite a change already being accept in the chromatic web interface (this PR does not touch components at all)

.github/workflows/test-and-demo.yaml

@@ -57,7 +57,7 @@ jobs:
       run: npm ci
     - name: Build  # only runs in case of cache hit, otherwise as part of npm ci
       if: steps.cache.outputs.cache-hit == 'true'
-      run: lerna bootstrap
+      run: npm run lerna bootstrap
 
   test:
     runs-on: ubuntu-latest