Update to upload-artifact v4 (#113)

There was a mismatch between upload and download actions causing release failure

Author: bingenito

.github/workflows/build.yml

@@ -47,11 +47,11 @@ jobs:
         dotnet pack src/Fdc3.AppDirectory/Finos.Fdc3.AppDirectory.csproj --no-build --configuration Release --output packages
 
     - name: Upload
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: package
         path: packages/*.nupkg
         if-no-files-found: error
 
     - name: Codecov
-      uses: codecov/codecov-action@v3.1.4
+      uses: codecov/codecov-action@v3.1.4