Remove some tests from helix retry list (#57539)

* Remove `CanSendAndReceiveUserMessagesFromMultipleConnectionsWithSameUser` from retry list.

#55954

* Remove `POST_ServerAbort_ClientReceivesAbort` from retry list.

#53294

Author: radical

eng/test-configuration.json

@@ -7,10 +7,8 @@
     {"testName": {"contains": "MaxRequestBufferSizeTests.LargeUpload" }}, // tries to manipulate the state of the server's buffer
     {"testName": {"contains": "CertificateChangedOnDisk"}}, // depends on FS event timing
     {"testName": {"contains": "CertificateChangedOnDisk_Symlink"}}, // depends on FS event timing
-    {"testName": {"contains": "POST_ServerAbort_ClientReceivesAbort"}},
     {"testName": {"contains": "CanLaunchPhotinoWebViewAndClickButton"}},
     {"testName": {"contains": "CheckInvalidHostingModelParameter"}},
-    {"testName": {"contains": "CanSendAndReceiveUserMessagesFromMultipleConnectionsWithSameUser"}},
     {"testName": {"contains": "CheckNewShimIsUsed"}}, // Issue: https://github.com/dotnet/aspnetcore/issues/57538
     {"testAssembly": {"contains": "IIS"}},
     {"testAssembly": {"contains": "Template"}},