Remove extraneous files from the CRD testdata

The internal_version stuff shouldn't've had its own go.mod or go
generate command -- it's intentionally part of the parent test suite.

Author: DirectXMan12

pkg/crd/testdata/internal_version/go.mod

@@ -13,8 +13,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-//go:generate controller-gen crd paths=. output:dir=.
-
 // +kubebuilder:skip
 package internal_version