Update upload-artifact to v4

Author: tmigot

.github/workflows/Breakage.yml

@@ -92,7 +92,7 @@ jobs:
               end;
             end'
 
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         with:
           name: pr
           path: pr/
@@ -134,7 +134,7 @@ jobs:
             fi
           done >> MSG
 
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         with:
           name: pr
-          path: pr/
+          path: pr/