[mono][debugger] Concurrency on execution context dictionary

[thaystg]

Follow up of this #87154

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Issue Details

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Follow up of this #87154

Author:	thaystg
Assignees:	-
Labels:	area-Debugger-mono
Milestone:	-

[radical]

This should work, right? Fine for a follow up PR.

Suggested change

	executionContext = contextBag.Where(context => context.Id == contextBag.Where(context => context.Destroyed == false).Max(context => context.Id)).FirstOrDefault();
	int maxId = contextBag.Where(context => context.Destroyed == false).Max(context => context.Id);
	executionContext = contextBag.Where(context => context.Id == maxId).FirstOrDefault();

[radical]

Use TryGetAndAddContext

[radical]

Failure is unrelated:

Test Run Aborted with error System.Exception: One or more errors occurred.
 ---> System.Exception: Unable to read beyond the end of the stream.
   at System.IO.BinaryReader.Read7BitEncodedInt()
   at System.IO.BinaryReader.ReadString()
   at Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.LengthPrefixCommunicationChannel.NotifyDataAvailable() in /_/src/Microsoft.TestPlatform.CommunicationUtilities/LengthPrefixCommunicationChannel.cs:line 90
   at Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.TcpClientExtensions.MessageLoopAsync(TcpClient client, ICommunicationChannel channel, Action`1 errorHandler, CancellationToken cancellationToken) in /_/src/Microsoft.TestPlatform.CommunicationUtilities/TcpClientExtensions.cs:line 53
   --- End of inner exception stack trace ---.