Update .github/workflows/diff.yml

Co-authored-by: Copilot <[email protected]>

Author: yifancong

.github/workflows/diff.yml

@@ -37,7 +37,6 @@ jobs:
       - name: Build Demo Project
         run: |
           cd website
-          pnpm install
           RSDOCTOR=1 pnpm run build
 
       - name: Report Compressed Size