factored out a final awaiter and a handle #134

Job	Run time
CMake: Disable build testing	55s
Compiler: GNU 14	45s
CMake: Disable example building	20s
Compiler: GNU 13	30s
Compiler: LLVM 20	56s
Compiler: LLVM 19	55s
Compiler: LLVM 18	51s
Unit: Ubuntu GNU 20 Default	1m 7s
Unit: Ubuntu GNU 20 MaxSan	1m 7s
Preset: gcc-debug on ubuntu-latest	29s
Unit: Ubuntu GNU 23 Default	1m 1s
Preset: gcc-release on ubuntu-latest	43s
Unit: Ubuntu GNU 23 MaxSan	1m 2s
Preset: appleclang-debug on macos-latest	24s
Preset: appleclang-release on macos-latest	33s
Preset: msvc-debug on windows-latest	1m 8s
Unit: Ubuntu GNU 26 Default	1m 0s
Preset: msvc-release on windows-latest	57s
Unit: Ubuntu GNU 26 MaxSan	1m 5s
Unit: Ubuntu LLVM 20 Default	1m 8s
Unit: Ubuntu LLVM 20 MaxSan	1m 16s
Unit: Ubuntu LLVM 23 Default	1m 7s
Unit: Ubuntu LLVM 23 MaxSan	1m 11s
Unit: Ubuntu LLVM 26 Default	1m 13s
Unit: Ubuntu LLVM 26 MaxSan	1m 10s
Unit: Windows MSVC 20 Default	1m 31s
Unit: Windows MSVC 20 MaxSan	1m 52s
Unit: Windows MSVC 23 Default	1m 37s
Unit: Windows MSVC 23 MaxSan	1m 35s
Unit: Windows MSVC 26 Default	1m 33s
Unit: Windows MSVC 26 MaxSan	1m 36s
Unit: Ubuntu GCC 23 Werror	1m 2s
Unit: Ubuntu GCC 23 Dynamic	1m 2s
create-issue-when-fault	0s
	34m 41s

Provide feedback