DRY checkout

.github/actions/setup/action.yml

@@ -4,6 +4,8 @@ description: Checkout, cache and install dependencies
 runs:
   using: composite
   steps:
+    - uses: actions/checkout@v4
+
     - name: Cache node_modules
       id: cache-node-modules
       uses: actions/cache@v4

.github/workflows/ci-e2e.yml

@@ -13,7 +13,6 @@ jobs:
     timeout-minutes: 15
 
     steps:
-      - uses: actions/checkout@v4
       - uses: ./.github/actions/setup
 
       - name: Cache Firebase emulators

.github/workflows/ci.yml

@@ -13,7 +13,6 @@ jobs:
     timeout-minutes: 5
 
     steps:
-      - uses: actions/checkout@v4
       - uses: ./.github/actions/setup
 
       - name: Lint