tests: disable `test-git-interop.t` with a requirements directive Note that the failures in this test affect all platforms. I don't like this, but the test has been broken for awhile because of dirstate API changes, and nobody noticed because the required `pygit2` package isn't installed on the CI systems. I did install it on the mac CI system, which triggers this failure. Disabling it is no worse than not running it due to the missing package, but at least this way the CI systems can get the package installed, and the test can be enabled and fixed eventually, without needing to alter the CI systems. The feature here is kind of abused. I thought about adding one specifically to test for CI, but didn't feel like doing it at this point. Maybe if we need to disable things to get the Windows CI off the ground (but that likely requires testing for CI + platform).