Fix data race leading to a deadlock when opening QuicStream

[rzikm]

Fixes #101233.
Fixes #100971.
Contributes to #101463

See original issue for the description of the deadlock scenario.

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[ManickaP]

Looks good, thanks for finding and fixing this!

[rzikm]

The original version was not a complete fix, it turns out that calling Complete on a Channel<T> will not complete the Completion if there are unread items in the channel.

runtime/src/libraries/System.Net.Quic/src/System/Net/Quic/QuicConnection.cs

Lines 433 to 436 in 79a7156

	if (_acceptQueue.Reader.Completion.IsFaulted || connectionAbortedByPeer)
	{
	await _acceptQueue.Reader.Completion.ConfigureAwait(false);
	}

So I added logic which will drain the channel once we are sure the streams inside have been shutdown. Please take another look.

[rzikm]

/azp run runtime-libraries-coreclr outerloop

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[ManickaP]

🥳

[CarnaViire]

Given the urgency, I won't poke at nits. Otherwise LGTM

[rzikm]

no QUIC or HTTP/3 failures in CI.

[rzikm]

/backport to release/8.0-staging

[github-actions]

Started backporting to release/8.0-staging: https://github.com/dotnet/runtime/actions/runs/9059881753

[github-actions]

@rzikm backporting to release/8.0-staging failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Fix data race leading to a deadlock.
Using index info to reconstruct a base tree...
M	src/libraries/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Http3.cs
M	src/libraries/System.Net.Quic/src/System/Net/Quic/QuicConnection.cs
M	src/libraries/System.Net.Quic/src/System/Net/Quic/QuicStream.cs
Falling back to patching base and 3-way merge...
Auto-merging src/libraries/System.Net.Quic/src/System/Net/Quic/QuicStream.cs
Auto-merging src/libraries/System.Net.Quic/src/System/Net/Quic/QuicConnection.cs
CONFLICT (content): Merge conflict in src/libraries/System.Net.Quic/src/System/Net/Quic/QuicConnection.cs
Auto-merging src/libraries/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Http3.cs
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Fix data race leading to a deadlock.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@rzikm an error occurred while backporting to release/8.0-staging, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.