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

.github/workflows/main.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [ main ]
 
+env:
+  TEX_NAME: Tesi.tex
+  PDF_NAME: Tesi.pdf
+
 jobs:
   build_latex:
     runs-on: ubuntu-latest
@@ -13,15 +17,22 @@ jobs:
       - name: Set up Git repository
         uses: actions/checkout@v4.2.2
 
-      - name: Compile LaTeX document
-        uses: xu-cheng/latex-action@3.2.0
-        with:
-          root_file: Tesi.tex
-          docker_image: ghcr.io/xu-cheng/texlive-full:20250101
+      - name: Install MiKTeX
+        run: |
+          curl -fsSL https://miktex.org/download/key | tee /usr/share/keyrings/miktex-keyring.asc > /dev/null
+          echo "deb [signed-by=/usr/share/keyrings/miktex-keyring.asc] https://miktex.org/download/ubuntu jammy universe" | sudo tee /etc/apt/sources.list.d/miktex.list
+          apt-get update
+          apt-get install miktex -y
+          miktexsetup --shared=yes finish
 
-      - name: Upload PDF file
-        if: github.ref == 'refs/heads/main'
-        uses: actions/upload-artifact@v4.6.0
+      - name: Enable automatic package installation
+        run: initexmf --set-config-value=[MPM]AutoInstall=yes
+
+      - name: Build LaTeX document
+        run: |
+          pdflatex -interaction=nonstopmode -halt-on-error ${{ env.TEX_NAME }} || (cat /root/.miktex/texmfs/data/miktex/log/pdflatex.log && exit 1)
+
+      - name: Upload PDF artifact
+        uses: actions/upload-artifact@v4
         with:
-          name: PDF
-          path: Tesi.pdf
+          path: ${{ env.PDF_NAME }}