Fix race conditions in TaskContext and CancellationContext cancellation #2286

Job	Run time
PSV.Linux.latest.gcc14.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	4m 37s
PSV.Linux.22.04.gcc9.Tests.CodeCov	7m 7s
PSV.Linux.24.04.gcc13.Tests	12m 11s
PSV.Linux.Android.22.04	6m 20s
PSV.Linux.22.04.gcc11.Tests	12m 23s
PSV.Linux.22.04.gcc9.Cpplint	11s
PSV.iOS.MacOS14.Xcode15.ARM64	5m 59s
PSV.Linux.latest.gcc14.Tests	14m 59s
PSV.Linux.22.04.gcc9.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	3m 5s
PSV.MacOS15.Xcode16.ARM64	5m 3s
PSV.Linux.22.04.gcc11.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 49s
PSV.Win.VC2022	9m 43s
PSV.Commit.Checker	7s
PSV.iOS.MacOS15.Xcode16.ARM64	8m 50s
PSV.Clang.Format.Checker	47s
PSV.Linux.22.04.clang.Tests	10m 28s
PSV.iOS.MacOS15.Xcode26.ARM64	7m 51s
	1h 52m 30s

Provide feedback