Drop support for Visual Studio 11 (2012) #1203

Job	Run time
Test build-std (aarch64-tvos)	2m 31s
Test build-std (aarch64-tvos-sim)	3m 15s
Test build-std (x86_64-tvos)	2m 33s
Clippy	11s
Test CUDA support	22s
MSRV (ubuntu-latest)	23s
Test (stable)	59s
Test (beta)	1m 0s
MSRV (windows-latest)	41s
Test (nightly)	1m 13s
Rustfmt	9s
Test (linux32)	1m 15s
Test (macos)	2m 20s
Test (aarch64-macos)	59s
Test (aarch64-ios)	1m 38s
Test (win32)	2m 21s
Test (win64)	2m 36s
Test (mingw32)	2m 47s
Test (mingw64)	2m 20s
Test (windows-2019)	3m 46s
Test (windows-aarch64, windows-latest, stable, aarch64-pc-windows-msvc, --no-run)	2m 20s
	35m 39s

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