rename olp/porting/optional.hpp into optional.h #2009

Job	Run time
PSV.MacOS15.Xcode16	3m 47s
PSV.iOS.MacOS13.Xcode15	12m 29s
PSV.Linux.22.04.gcc9.Cpplint	9m 5s
PSV.Clang.Format.Checker	42s
PSV.MacOS13.Xcode15.x86_64	3m 41s
PSV.Linux.latest.gcc14.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	4m 8s
PSV.MacOS14.Xcode15	4m 47s
PSV.Win.VC2022	10m 0s
PSV.Linux.22.04.gcc9.Tests.CodeCov	10m 33s
PSV.iOS.MacOS13.Xcode14	11m 48s
PSV.Linux.22.04.gcc11	8m 21s
PSV.Linux.22.04.gcc9.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	2m 38s
PSV.Linux.22.04.gcc11.OLP_SDK_ENABLE_DEFAULT_CACHE=OFF	3m 2s
PSV.Linux.22.04.clang	9m 15s
PSV.Linux.Android.22.04	6m 14s
PSV.Linux.22.04.gcc13	8m 54s
PSV.iOS.MacOS15.Xcode16	9m 20s
PSV.Commit.Checker	5s
PSV.iOS.MacOS14.Xcode15	6m 13s
	2h 5m 2s

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