Local git config is ignored for git operations

[sphanley]

Hello! My team is using this plugin and it's largely working great for us, but I've run into an issue recently: I'm trying to set an extra header to be included on the git requests made by the plugin, however this only works if I put it in the global git config, which isn't ideal in our CI environment as it requires more cleanup. I would expect the local git config in the context where the plugin is called to be honored, but values in that config file do not seem to be loaded at runtime.