Users will still be able to opt out:
* for unit tests, by providing the `cargo_cfg_overrides=-test` extractor
option
* for integration tests, by excluding the test files from the analysis
using `paths-ignore` in the codescanning configuration file
We may want to revisit whether we want a single option for both. Also
further work will be needed to restrict our security queries to non-test
code on the QL side.
