Create README for Running Non-production Builds

[SableRaf]

Non-production builds require additional setup, especially on macOS, where they are blocked due to missing notarization. Users must manually remove quarantine attributes (xattr -d com.apple.quarantine ./Processing.app).

Task

• Create an INSTRUCTIONS_FOR_TESTING.md file.
• Write step-by-step instructions for running non-production builds.
• Update the CI/CD to include the instructions file in non-production builds.