This diff introduces the following changes to the Cargo `build.rs`:
- Removing the testing building of the `hello.c` [[ https://phab.comm.dev/D5807?id=19130#inline-40604 | based on the comment ]];
- Increasing the C++ standard to 17, [[ https://phab.comm.dev/D5899?id=19462#inline-39787 | because RN now supports it ]].
Linear task: [[ https://linear.app/comm/issue/ENG-2536/refactoring-and-minor-fixes-of-the-native-rust-library | ENG-2536 ]]