ci(github): fix build script in examples/cactus-example-cbdc-bridging-frontend

[ruzell22]

Description

The current react build scripts are not at all producing the structure of the ./dist folder that we need when running yarn run configure and yarn run custom-checks. Tests and discussion can be further found in #3675

Refer to this comment: #3675 (review)

Acceptance Criteria

1. Build script of the package is producing the expected structure of ./dist folder
2. yarn run custom-checks is running successfully and is passing on this specific package with no error