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

.github/workflows/main.yml

@@ -9,6 +9,8 @@ on:
 jobs:
   build_latex:
     runs-on: ubuntu-latest
+    container:
+      image: ubuntu:latest
     steps:
       - name: Install Node.js
         run: |
@@ -27,9 +29,6 @@ jobs:
           apt-get install miktex -y
           miktexsetup --shared=yes finish
 
-      - name: Update MiKTeX
-        run: miktexsetup --update
-
       - name: Build LaTeX document
         run: |
           pdflatex -interaction=nonstopmode -halt-on-error Tesi.tex || (cat /root/.miktex/texmfs/data/miktex/log/pdflatex.log && exit 1)