…ation

Co-authored-by: Evangelink <[email protected]>

The test was using _testMethodInfo which has a 1-hour timeout set,
causing IsTimeoutSet to be true. This routes through
ExecuteInternalWithTimeoutAsync's non-cooperative path which runs
ExecuteInternalAsync on a separate thread pool thread where
SynchronizationContext.Current is null.

Create a local TestMethodInfo without a timeout so the test goes
through the direct ExecuteInternalAsync path on the SC's thread,
which is the code path the production fix targets.

…handling, TestCleanup test, and fix comment accuracy

Co-authored-by: Evangelink <[email protected]>

… reentrancy

…t, use FluentAssertions, suppress CA2007

…dispose, fix null! and AwesomeAssertions

…to cleanup test, bounded Join, fix CS0160