chore: Remove inconsistent test

[mattcreaser]

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes:
Removes the testNoNotifyImmediateCancel test. This test has a threading race condition (easily verifiable by adding a Thread.sleep(100) call to the test body) causing it to inconsistently fail on CI.

Also updated the code coverage workflow to save test results if the job fails, allowing us to see the particular failure which will help in tracking down other test issues.

How did you test these changes?

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist

• Added Unit Tests
• Added Integration Tests
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Ensure commit message has the appropriate scope (e.g fix(storage): message, feat(auth): message, chore(all): message)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.26%. Comparing base (d9eb7a9) to head (8c61c48).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3131      +/-   ##
==========================================
+ Coverage   54.24%   54.26%   +0.02%     
==========================================
  Files        1038     1040       +2     
  Lines       32008    32062      +54     
  Branches     4703     4712       +9     
==========================================
+ Hits        17364    17400      +36     
- Misses      12805    12822      +17     
- Partials     1839     1840       +1     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.