chore: fix build replacing npm by pnpm (#136)

Author: francescarpi

.github/workflows/ci.yml .github/workflows/build.yml.github/workflows/ci.yml renamed to .github/workflows/build.yml

@@ -27,10 +27,10 @@ jobs:
           node-version-file: '.nvmrc'
 
       - name: Install dependencies
-        run: npm install
+        run: pnpm install
 
       - name: Build with Astro
-        run: npm run build
+        run: pnpm run build
 
       - name: Upload artifact
         if: github.event_name != 'pull_request'