ci: switch npm publish to OIDC provenance

.github/workflows/publish.yml

@@ -4,6 +4,10 @@ on:
   push:
     tags: [ "v*" ]
 
+permissions:
+  id-token: write
+  contents: read
+
 env:
   CARGO_TERM_COLOR: always
 
@@ -42,8 +46,5 @@ jobs:
 
       - name: Publish to npm
         run: |
-          echo "//registry.npmjs.org/:_authToken=${{ secrets.NPM_TOKEN }}" > pkg/.npmrc
           cd pkg
-          npm publish --access public
+          npm publish --access public --provenance
-        env:
-          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}