CompatHelper: add new compat entry for "MathProgBase" at version "0.7"

[github-actions[bot]]

This pull request sets the compat entry for the MathProgBase package to 0.7.

This is a brand new compat entry. Previously, you did not have a compat entry for the MathProgBase package.

Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.