fix: restore NPM_TOKEN auth and add --access public for scoped package publish (#7475)

* fix: explicitly dispatch CI after tag push to build release binaries

GITHUB_TOKEN pushes do not trigger new workflow runs (GitHub prevents
recursive loop triggers). This means the tag push from the release
workflow never triggered osrm-backend.yml, so no binaries were built
or uploaded to the release assets.

Changes:
- Add workflow_dispatch trigger to osrm-backend.yml
- Add 'actions: write' permission to release workflow
- After pushing the tag, explicitly dispatch osrm-backend.yml on the
  tag ref; CI runs with GITHUB_REF=refs/tags/v* so PUBLISH=On and
  prebuilt binaries are built and uploaded
- Restore NODE_AUTH_TOKEN and add --access public for scoped npm package

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: remove redundant NPM_TOKEN and --access public from publish step

publishConfig.access=public is already set in package.json, so --access
public is redundant. OIDC via setup-node handles authentication when
id-token: write is set.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: DennisOSRM

.github/workflows/osrm-backend.yml

@@ -8,6 +8,7 @@ on:
   pull_request:
     branches:
       - master
+  workflow_dispatch:
 
 env:
   CCACHE_TEMPDIR: /tmp/.ccache-temp

.github/workflows/release-monthly.yml

@@ -26,6 +26,7 @@ jobs:
     permissions:
       contents: write
       id-token: write
+      actions: write
     steps:
       - uses: actions/checkout@v6
         with:
@@ -133,6 +134,15 @@ jobs:
           git push origin "$BRANCH"
           git push origin "${{ steps.version.outputs.tag }}"
 
+      - name: Trigger CI for tag
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          # GITHUB_TOKEN pushes don't trigger workflow runs (prevents loops).
+          # Explicitly dispatch CI on the tag so binaries get built and uploaded.
+          gh workflow run osrm-backend.yml --ref "${{ steps.version.outputs.tag }}"
+          echo "Dispatched osrm-backend.yml on ${{ steps.version.outputs.tag }}"
+
       - name: Generate changelog
         id: changelog
         run: |