I doubt this is actionable on your side (#[googletest::test] expands to something that looks very reasonable), but I thought you might want to be aware of it.
I've opened an issue upstream with the RustRover team, which you can track: https://youtrack.jetbrains.com/issue/RUST-13162/False-positive-Unused-import-even-though-theyre-used-in-googletesttest-case