"My Items" interceptor test failing

[scottbell]

Summary

This test appears to be failing in its cleanup:
https://github.com/nasa/openmct/blob/master/src/plugins/myItems/pluginSpec.js#L82

Here's the output from the daily build:
https://app.circleci.com/pipelines/github/nasa/openmct/7078/workflows/39881ff1-24c2-4914-8bf5-ae894c540829/jobs/19835

the plugin
    ✓ when installed, adds "My Items" to the root (39ms)
    adds an interceptor that returns a "My Items" model for
      ✓ missing objects (61ms)
Chrome Headless 96.0.4664.45 (Linux x86_64) ERROR
  An error was thrown in afterAll
  Unhandled promise rejection: Object provider does not support saving thrown
Chrome Headless 96.0.4664.45 (Linux x86_64) ERROR
  An error was thrown in afterAll
  Unhandled promise rejection: Object provider does not support saving thrown

I think it was caused by this PR:
#4471

Note the test sometimes passes, so it appears to be a timing error.

Expected vs Current Behavior

The test should consistently pass.

Impact Check List

• Data loss or misrepresented data?
• Regression? Did this used to work or has it always been broken?
• Is there a workaround available?
• Does this impact a critical component?
• Is this just a visual bug?

Steps to Reproduce

1. git checkout master
2. npm run test
3. Observe the test failure
4. If the test does not fail, repeat step 3 until it does.

Environment

• Open MCT Version: master
• Deployment Type: npm dev
• OS: Linux/Windows
• Browser: Chrome Headless

[shefalijoshi]

This is fixed as part of #4310, but in master. That said, I think it's ok to close this for 1.8.1