feat: update MiKTeX package database and add release token for PDF builds

.github/workflows/main.yml

@@ -25,6 +25,9 @@ jobs:
           apt-get install miktex -y
           miktexsetup --shared=yes finish
 
+      - name: Update MiKTeX package database
+        run: miktex packages update-package-database && miktex packages update
+
       - name: Enable automatic package installation
         run: initexmf --set-config-value=[MPM]AutoInstall=yes
 
@@ -42,4 +45,5 @@ jobs:
           files: ${{ env.PDF_NAME }}
           tag_name: latest
           body: |
-            PDF document built from latest LaTeX source.
+            PDF document built from latest LaTeX source.
+          token: ${{ secrets.RELEASE_TOKEN }}