Tests belong in the project they're testing. Test tooling belongs elsewhere. It's not clear what your setup is, but it sounds like the tests themselves live in another repo. That's bad. It's not bad to have a separate repo for your tooling/test runners. As you've just seen, new tests need to go out simultaneously with new code.
Yes, tests are with the code as are test resources that are product specific. In addition to those there are a lot of resources that are shared across all or most products that sit in the test automation core.
