debug_traceCallMany: materialize simple call traces

[BZO95]

Changes

• Materialize simple-path debug_traceCallMany bundle traces before the request timeout source is disposed.
• Add regression coverage for enumerating traces while the cancellation token is still usable.

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Description

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Notes on testing

• Added Debug_traceCallMany_materializes_simple_path_before_timeout_source_is_disposed.
• Ran git diff --check.
• .NET build/test intentionally skipped by user request.

Documentation

Requires documentation update

• Yes
• No

Requires explanation in Release Notes

• Yes
• No

[LukaszRozmej]

Why? Avoiding those allocations was intentional.

[LukaszRozmej]

Closing in favor of #11429
Thank you for bringing the issue to our attention

[BZO95]

@LukaszRozmej 👍 Thanks, that makes sense. My intent was to keep the timeout CTS alive for lazy serialization, but I missed that the allocation-free streaming path was intentional.