ci: upgrade npm before publishing for OIDC trusted publishing support

Node 20 ships npm 10.x, but npm 11.5.1+ is required to perform OIDC
trusted publishing. Without it, 'npm publish' falls back to the
token-auth flow with no token, and npm's registry returns 404 on PUT
(it hides package existence from unauthenticated callers), producing
the misleading 'Not found' error we saw on @cooklang/cooklang.

Author: dubadub

.github/workflows/release.yml

@@ -776,6 +776,9 @@ jobs:
           node-version: '20'
           registry-url: 'https://registry.npmjs.org'
 
+      - name: Upgrade npm for OIDC trusted publishing support
+        run: npm install -g npm@latest
+
       - name: Install wasm-pack
         run: cargo install wasm-pack --locked || true