Throw if CancellationToken passed to CancellableThrough is not already cancelled

[rosenbjerg]

No description provided.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.56%. Comparing base (1c4333e) to head (736420e).
⚠️ Report is 185 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #600      +/-   ##
==========================================
- Coverage   71.20%   69.56%   -1.65%     
==========================================
  Files         117      123       +6     
  Lines        2973     3545     +572     
  Branches      284      311      +27     
==========================================
+ Hits         2117     2466     +349     
- Misses        751      964     +213     
- Partials      105      115      +10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.