⚙️ config(ci): Configure restore key for puppeteer cache in test work…

…flow.

This fixes #865 for good.

Since `meteor-actions/install` now can skip the installation of cached
packages using restore keys, it can happen that `node_modules/puppeteer`
is restored from cache while its `chromium` download is not.

With this commit, we ensure that the weakest restore key for `chromium`
is at least as weak as the weakest restore key for
`node_modules/puppeteer`.

Maybe an alternative would be to instruct `puppeteer` to install
chromium under `node_modules`? But for now, this is good enough.

.github/workflows/test.yml

@@ -43,6 +43,8 @@ jobs:
         with:
           path: ~/.cache/puppeteer
           key: ${{ runner.os }}-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ env.cache-name }}-
 
       - name: Install 💾
         uses: ./.github/actions/install