CMakeLists.txt, script/[cibuild,docker-entrypoint.sh]: Adj to GH Actions

[stephengtuggy]

Thank you for submitting a pull request and becoming a contributor to Vega Strike: Upon the Coldest Sea.

Please answer the following:

Code Changes:

• [ ] Have the PR Validation Tests been run? See https://github.com/vegastrike/Vega-Strike-Engine-Source/wiki/Pull-Request-Validation
• [ ] This is a documentation change only
• [X] This is a CI/CD/build system change only

Issues:

• Please list any related issues

  43

Purpose:

• What is this pull request trying to do? Finish the changes required to get vsUTCS v0.7.x to build for release on GitHub Actions
• What release is this for? 0.7.x
• Is there a project or milestone we should apply this to? 0.7.x