ci: fix size workflow setup

checkout needs to happen before pnpm install

.github/workflows/size.yml

@@ -9,9 +9,9 @@ jobs:
     env:
       CI_JOB_NUMBER: 1
     steps:
+      - uses: actions/checkout@v1
       - name: Install pnpm
         uses: pnpm/action-setup@v2
-      - uses: actions/checkout@v1
       - uses: andresz1/size-limit-action@v1
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}