JobMonitor: Use fluent assertions to handle random order of results

[premun]

Resolves problems with comparing results that come in asynchronously

[Copilot]

Pull request overview

This PR updates Helix JobMonitor-related tests to use AwesomeAssertions equivalency assertions so validations are insensitive to nondeterministic ordering, reducing test flakiness in the Helix SDK test suite.

Changes:

• Replace order-dependent Assert.Equal(...Order()) patterns with Should().BeEquivalentTo(...) for uploaded job names.
• Replace explicit sorting for cancellation assertions with order-insensitive equivalency assertions.
• Update AzureDevOpsService test to validate processed job names without ordering.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Microsoft.DotNet.Helix/Sdk.Tests/Microsoft.DotNet.Helix.Sdk.Tests/JobMonitorRunnerTests.cs	Switches multiple assertions on job-name collections to order-insensitive equivalency checks to avoid random-order test failures.
src/Microsoft.DotNet.Helix/Sdk.Tests/Microsoft.DotNet.Helix.Sdk.Tests/AzureDevOpsServiceTests.cs	Uses order-insensitive equivalency for processed Helix job name set assertions.