Update actions/checkout and actions/upload-artifact versions in workflow

.github/workflows/main.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up Git repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v4.2.2
 
       - name: Compile LaTeX document
         uses: xu-cheng/latex-action@3.2.0
@@ -21,7 +21,7 @@ jobs:
 
       - name: Upload PDF file
         if: github.ref == 'refs/heads/main'
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v4.6.0
         with:
           name: PDF
           path: Tesi.pdf