[test] Method not found Xunit.Sdk.XunitException..ctor

[mdh1418]

Test: AssemblyLoad_ProducesEvents
Error Message: System.MissingMethodException : Method not found: 'Void Xunit.Sdk.XunitException..ctor(System.String, System.String)'.
Configuration: Ubuntu_20_04_x64_Debug

Stack Trace:

   at Microsoft.DotNet.RemoteExecutor.RemoteExecutionException..ctor(String stackTrace)
   at Microsoft.DotNet.RemoteExecutor.RemoteInvokeHandle.Dispose(Boolean disposing) in /_/src/Microsoft.DotNet.RemoteExecutor/src/RemoteInvokeHandle.cs:line 231
   at Microsoft.DotNet.RemoteExecutor.RemoteInvokeHandle.Dispose() in /_/src/Microsoft.DotNet.RemoteExecutor/src/RemoteInvokeHandle.cs:line 57
   at EventPipe.UnitTests.Common.RemoteTestExecutorHelper.RunTestCaseAsync(Action testCase, ITestOutputHelper output) in /__w/1/s/src/tests/eventpipe/common/RemoteTestExecutorHelper.cs:line 34
   at EventPipe.UnitTests.LoaderEventsValidation.LoaderEventsTests.AssemblyLoad_ProducesEvents() in /__w/1/s/src/tests/eventpipe/LoaderEvents.cs:line 37
   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_0(Object state)

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=668134&view=ms.vss-test-web.build-test-results-tab&runId=16576362&resultId=100111&paneView=debug

PullRequest where test is failing #4616 seems unrelated, probably a flakey test that hadn't failed in neighboring builds