fix erroneous mouse motion when alt-tabbing in CS2 #2550

Job	Run time
Create test plan	9s
level1 / Haiku	1m 51s
level2 / Android (CMake, lean)	3m 7s
level2 / NetBSD	2m 35s
level2 / RISC OS	1m 29s
level2 / Windows (MSVC, ARM64)	3m 24s
level2 / Ubuntu 20.04	4m 8s
level2 / MacOS (Framework) (arm64)	2m 20s
level2 / Ubuntu 20.04 (Intel oneAPI)	6m 36s
level2 / Nintendo 3DS	1m 58s
level2 / PowerPC	1m 46s
level2 / Windows (msys2, clang64)	5m 36s
level2 / Windows (msys2, mingw32)	8m 7s
level2 / MacOS (GNU prefix)	3m 39s
level2 / Sony PlayStation Portable	3m 43s
level2 / Ubuntu 20.04 (Intel Compiler)	4m 40s
level2 / Sony PlayStation 2	4m 58s
level2 / Windows (MSVC, clang-cl x86)	5m 48s
level2 / FreeBSD	2m 42s
level2 / Android (CMake)	3m 10s
level2 / Ubuntu 22.04	4m 49s
level2 / iOS (CMake & xcode)	2m 10s
level2 / Android (Gradle)	2m 4s
level2 / Windows (msys2, mingw64)	7m 55s
level2 / Steam Linux Runtime (Sniper)	3m 2s
level2 / tvOS (CMake & xcode)	1m 54s
level2 / Windows (msys2, ucrt64)	8m 5s
level2 / Windows (MSVC, ARM)	2m 34s
level2 / Emscripten	8m 39s
level2 / Windows (MSVC, clang-cl x64)	5m 15s
level2 / PowerPC64	1m 53s
level2 / Sony PlayStation Vita (GLES w/ PVR_PSP2)	3m 26s
level2 / MacOS (Framework) (x64)	5m 23s
level2 / Windows (MSVC, x86)	4m 42s
level2 / Android (Android.mk)	1m 20s
level2 / Sony PlayStation Vita (GLES w/ pib)	3m 10s
level2 / Windows (msys2, clang32)	6m 48s
level2 / GDK (MSVC, x64)	1m 53s
level2 / LoongArch64	2m 51s
level2 / Windows (MSVC, x64)	4m 57s
	2h 34m 36s

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