Refactor GitHub Actions workflow to install LaTeX dependencies and build document directly, updating artifact upload step

.github/workflows/main.yml

@@ -32,14 +32,7 @@ jobs:
         run: |
           pdflatex -interaction=nonstopmode -halt-on-error ${{ env.TEX_NAME }} || (cat /root/.miktex/texmfs/data/miktex/log/pdflatex.log && exit 1)
 
-      - name: Check for PDF artifact
-        run: file ${{ env.PDF_NAME }} || grep -q ' PDF '
-
-      - name: Release PDF artifact
-        uses: softprops/action-gh-release@v2
+      - name: Upload PDF artifact
+        uses: actions/upload-artifact@v4
         with:
-          files: ${{ env.PDF_NAME }}
-          #token: ${{ secrets.GITHUB_TOKEN }}
-          tag_name: latest
-          body: |
-            PDF document built from LaTeX source.
+          path: ${{ env.PDF_NAME }}