ci: add npm ci step

Author: anlyyao

.github/workflows/pr-compressed-size.yml

@@ -11,6 +11,9 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
+
+      - run: npm ci
+
       - uses: preactjs/compressed-size-action@v2
         with:
           repo-token: '${{ secrets.GITHUB_TOKEN }}'