changed actions/upload-artifact@v3 to @v4 build.yml

V3 will be deprecated soon

Author: mmpcn

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
     steps:
 
     - name: Checkout the repository
-      uses: actions/checkout@v1
+      uses: actions/checkout@v4
       with:
         submodules: true
 
@@ -39,7 +39,7 @@ jobs:
         test -f ${{ env.doc_name }}.bbl
 
     - name: Keep the PDF artefact
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: PDF Preview
         path: ${{ env.doc_name }}.pdf