fix(ci): use npm pkg delete instead of set to empty string

npm pkg set scripts.prepublishOnly="" fails on newer npm versions
because the empty value is not recognized as a valid key=value pair.
Use npm pkg delete to remove the key entirely instead.

Author: github-actions[bot]

.github/workflows/publish.yml

@@ -158,7 +158,7 @@ jobs:
           echo "Publishing version $VERSION"
 
       - name: Disable prepublishOnly
-        run: npm pkg set scripts.prepublishOnly=""
+        run: npm pkg delete scripts.prepublishOnly
 
       - name: Download native artifacts
         uses: actions/download-artifact@v4