Update to actions/<upload/download>-artifact@v4

Author: duckdoom5

.github/workflows/main.yml

@@ -90,9 +90,12 @@ jobs:
         shell: bash
         run: build/build.sh prepack -platform $PLATFORM
 
-      - uses: actions/upload-artifact@v3
+      - name: Upload Artifacts
+        uses: actions/upload-artifact@v4
         with:
           name: intermediate
+          retention-days: 7
+          overwrite: true
           path: |
             artifacts
             include/**/*.h
@@ -116,7 +119,7 @@ jobs:
       - name: Set version
         run: nbgv cloud --all-vars
 
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: intermediate
 
@@ -129,7 +132,7 @@ jobs:
         run: build/build.sh pack
 
       - name: Upload package
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: CppSharp.nupkg
           path: |