Mark WINAPI as __stdcall #22

Job	Run time
ubuntu-22.04, default debug	19s
windows-2022, default debug	54s
macos-latest, default debug	29s
windows-2022, gcc debug	1m 3s
ubuntu-22.04, clang debug	21s
ubuntu-22.04, sanitize debug	38s
windows-2022, sanitize+asanonly debug	1m 22s
ubuntu-22.04, clang+sanitize debug	51s
ubuntu-22.04, clang+msan debug	1m 58s
windows-2022, clang-cl+sanitize debug	1m 32s
windows-2022, clang-cl+msan debug	1m 38s
ubuntu-22.04, default release	22s
windows-2022, default release	1m 11s
macos-latest, default release	25s
windows-2022, gcc release	1m 12s
ubuntu-22.04, clang release	24s
ubuntu-22.04, sanitize release	36s
windows-2022, sanitize+asanonly release	1m 29s
ubuntu-22.04, clang+sanitize release	36s
ubuntu-22.04, clang+msan release	25s
windows-2022, clang-cl+sanitize release	1m 38s
windows-2022, clang-cl+msan release	1m 33s
	20m 56s

Provide feedback