Test plans no longer accessible in Xcode.

I have a project where I've been using test plans for the past month (Xcode 13.4.1).

Then today they just stopped being available. I was checking one of my schemes and noticed that it didn't have the test plan associated with it. So I went to the Build section and clicked the Add Target + button, but my Test plan files didn't show up. So I went to the Test section and it was showing the test target, not the plan. So I removed the target and hit the Add test target + button and again none of my test plans appeared. The test navigator is no longer showing the test plan above the tests.

So I looked in Product - Test Plan and the only enabled menu item was to Create a Test plan. So I tried that and created and brand new test plan. When back to the scheme and still could not add it to the scheme. Nor could I get it to display at the top of the test target.

I checked the git changes and it showed a bunch of new schemes which I hadn't created and all my schemes being changed back to from . Yet when I go back to the scheme I'm not offered any option to enable test plans again. And the Product - Test Plan menu items remain disabled.

I've tried clearing derived, restarting Xcode, wiping all my test plans and rebuilding but nothing I do is enabling the test plans again.

How do I fix this?

Test plans no longer accessible in Xcode.
 
 
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