CI: Migrate from GitHub Actions workflow to Dockerfile

[seclerp]

Currently, there are some disadvantages to using GitHub Actions:

• It's hard to test workflows locally in the same environment as GitHub Actions (act will not work on complex workflows like ours)
• Vendor lock. It's hard to migrate into Space if needed because Space Automation is not feature-rich yet
• There is already an image specially created for Rider plugins build: seclerp.rider-plugin-ubuntu