Fix Chromatic on PR

.github/workflows/chromatic.yml

@@ -1,10 +1,14 @@
 name: "Chromatic"
 
 on:
-    push:
-        branches:
-            - next
-            - graphql
+  push:
+      branches:
+          - next
+          - graphql
+  pull_request:
+      branches:
+          - next
+          - graphql
 
 jobs:
   chromatic:
@@ -15,10 +19,18 @@ jobs:
             node-version: [20.x]
     steps:
         - name: Checkout
+          if: github.event_name == 'push'
           uses: actions/checkout@v4
           with:
             fetch-depth: 0
 
+        - name: Checkout (PR)
+          if: github.event_name == 'push'
+          uses: actions/checkout@v4
+          with:
+            fetch-depth: 0
+            ref: ${{ github.event.pull_request.head.ref }}
+
         - name: Restore Yarn cache
           uses: actions/cache@v4
           with: