enables test_gh_8599 test (#8984)

### Description

I noticed in the CI logs a warning that this was an unused function.
Looks like we just forgot the test annotation in
#8825

### Testing Instructions

Tests pass.

crates/turborepo-repository/src/inference.rs

@@ -348,6 +348,7 @@ mod test {
         );
     }
 
+    #[test]
     fn test_gh_8599() {
         // TODO: this test documents existing broken behavior, when we have time we
         // should fix this and update the assertions