fix: specify GitHub Packages registry explicitly in npm publish

npm publish was defaulting to registry.npmjs.org instead of
npm.pkg.github.com, causing ENEEDAUTH errors. Adding --registry
flag ensures the correct registry is used regardless of .npmrc
resolution in workspace setups.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: yokotaso

.github/workflows/publish-gpr.yaml

@@ -23,6 +23,6 @@ jobs:
       - name: Set version
         if: ${{ inputs.version != '' }}
         run: npm version "${{ inputs.version }}" --no-git-tag-version -w pkgs/typed-api-spec
-      - run: npm publish -w pkgs/typed-api-spec --access public
+      - run: npm publish -w pkgs/typed-api-spec --access public --registry https://npm.pkg.github.com
         env:
           NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}