move windows related header to private #2860

Job	Run time
downstream	42m 10s
clang-sanitizers (,thread)	6m 40s
freebsd	6m 36s
clang-sanitizers (,address,undefined)	6m 58s
linux-byo-crypto	2m 49s
linux-compat (manylinux1-x64)	5m 15s
linux-compat (manylinux1-x86)	5m 47s
linux-compiler-compat (clang-3)	6m 18s
linux-debug	5m 52s
linux-shared-libs	6m 3s
linux-compat (manylinux2014-x64)	6m 0s
linux-compiler-compat (clang-6)	6m 34s
linux-compat (manylinux2014-x86)	6m 52s
linux-compiler-compat (clang-8)	6m 56s
linux-compat (fedora-34-x64)	5m 56s
linux-compiler-compat (clang-9)	6m 58s
linux-compat (opensuse-leap)	7m 12s
macos-debug (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=ON)	1m 20s
linux-compiler-compat (clang-10)	7m 5s
macos (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=ON)	1m 14s
linux-compat (rhel8-x64)	6m 5s
macos-debug (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)	2m 27s
linux-compiler-compat (clang-11)	6m 50s
macos (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)	2m 28s
linux-compat (al2-x64)	6m 19s
linux-compiler-compat (gcc-4.8)	6m 43s
linux-compiler-compat (gcc-5)	6m 19s
macos-x64	2m 49s
linux-compiler-compat (gcc-6)	6m 40s
openbsd	10m 8s
windows	3m 1s
linux-compiler-compat (gcc-7)	6m 14s
linux-compiler-compat (gcc-8)	6m 57s
windows-app-verifier	2m 57s
windows-debug	2m 43s
windows-shared-libs	2m 22s
windows-vc14 (x86)	1m 12s
windows-vc14 (x64)	1m 13s
	3h 54m 2s

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