cmake/Tests: enable Cargo features

For unknown reasons, we don't enable Cargo features on the test target.
Let's try to, simplifying things overall.

Ref: https://github.com/fish-shell/fish-shell/issues/12120#issuecomment-3627842316

cmake/Tests.cmake

@@ -61,6 +61,7 @@ add_custom_target(fish_run_tests
             ${Rust_CARGO}
             test
             --no-default-features
+            --features=${FISH_CARGO_FEATURES}
             ${CARGO_FLAGS}
             --workspace
             --target-dir ${rust_target_dir}