Update upload-artifact GitHub action

Author: Nicolas Hiot

.github/workflows/latex.yml

@@ -18,7 +18,7 @@ jobs:
             main.tex
             slides/thesis-slides.tex
       - name: Upload PDF file
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: Thesis
           path: |