ci: Improve GitHub Actions workflow for automated builds and testing

[gto90]

Purpose

This pull request introduces a comprehensive GitHub Actions workflow to automate the build and test processes for DigiByte Core. This enhancement improves the development workflow by providing automated testing and validation of code changes.

Changes Made

• Added new GitHub Actions workflow file (.github/workflows/digibyte-ci.yml) that:
  • Implements caching for pip, BerkeleyDB, and depends build
  • Sets up comprehensive build environment with required dependencies
  • Configures automated build process for Ubuntu
  • Runs test suite using make check
  • Uploads test logs as artifacts on failure

Testing

The workflow has been tested by:

• Verifying successful builds on Ubuntu
• Confirming proper cache implementation
• Ensuring test suite execution works as expected
• Validating artifact upload functionality

[JaredTate]

cACK. Great stuff @gto90. Will be great to have some automated tests for all pull requests moving forward.

[ycagel]

cACK. Amazing work @gto90.