This diff is a part of the flat diffs stack to transform the current Tunnelbroker project into a Rust app by calling the current C++ codebase from Rust. The related transition task is [[ https://linear.app/comm/issue/ENG-1072 | ENG-1072 ]].
This diff makes changes to the global `.gitignore` file to remove the old build cache directory, append an updated one, and remove the unused anymore config file from the ignore list.
The project directory structure task and discussion: [[ https://linear.app/comm/issue/ENG-2083 | ENG-2083 ]]
**CI Notice:**
The CI will fail on these diffs until the end of the stack with the changes to CI build commands. This stack will be landed all in one to prevent CI from failing on diffs out of this stack.