fix: add +x to product.json in build-vscode

While testing a pre-release, there seems to be a bug with the file
permissions for `product.json`. Adding `chmod +x` to see if that fixes
it.

ci/build/build-vscode.sh

@@ -90,6 +90,8 @@ main() {
 EOF
   ) > product.json
 
+  chmod +x product.json
+
   # Any platform here works since we will do our own packaging.  We have to do
   # this because we have an NPM package that could be installed on any platform.
   # The correct platform dependencies and scripts will be installed as part of