Cleanup FMT_ASSERT #6016

Job	Run time
build (windows-2019, Win32, v142, 17, Debug)	1m 46s
build (windows-2019, Win32, v142, 17, Release)	2m 32s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 24s
mingw (mingw64)	3m 44s
build (windows-2019, Win32, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 25s
mingw (ucrt64)	3m 58s
build (windows-2019, x64, v140, 14, Debug)	1m 22s
build (windows-2019, x64, v140, 14, Release)	1m 49s
build (windows-2019, x64, v141, 17, Debug)	1m 23s
build (windows-2019, x64, v141, 17, Release)	2m 28s
build (windows-2019, x64, v142, 17, Debug)	1m 47s
build (windows-2019, x64, v142, 17, Release)	2m 11s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Debug)	1m 27s
build (windows-2019, x64, v142, 17, -DBUILD_SHARED_LIBS=ON, Release)	2m 21s
build (windows-2019, x64, v142, 20, Debug)	1m 46s
build (windows-2019, x64, v142, 20, Release)	3m 12s
build (windows-2022, x64, v143, Debug, 20)	2m 1s
	37m 36s

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