GHA: scope the publishing workflow to npm environment

See https://docs.github.com/en/actions/how-tos/write-workflows/choose-what-workflows-do/deploy-to-environment

Author: generalmimon

.github/workflows/publish.yml

@@ -45,6 +45,9 @@ jobs:
     runs-on: ubuntu-latest
     needs:
       - build
+    environment:
+      name: npm
+      url: https://www.npmjs.com/package/kaitai-struct
     permissions:
       id-token: write  # Required for OIDC (see https://docs.npmjs.com/trusted-publishers)
     steps: