Update CI workflow file

.github/workflows/ci.yml

@@ -2,15 +2,15 @@ name: CI
 
 on:
   pull_request:
+    branches: [main]
   push:
     branches: [main]
 
 jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
@@ -54,11 +54,7 @@ jobs:
       RAILS_ENV: test
 
     steps:
-      - name: Install packages
-        run: sudo apt-get update && sudo apt-get install --no-install-recommends -y google-chrome-stable curl libjemalloc2 libsqlite3-0 libvips
-
-      - name: Checkout code
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1