Make npm-postinstall.sh more robust

ci/steps/release-static.sh

@@ -4,6 +4,9 @@ set -euo pipefail
 main() {
   cd "$(dirname "$0")/../.."
 
+  # https://github.com/actions/upload-artifact/issues/38
+  chmod +x $(grep -rl '^#!/.\+' release)
+
   yarn release:static
   yarn test:static-release
   yarn package