v0.12.0: update to rustls 0.22, address breaking changes #1325

Job	Run time
Build+test (clang, stable, ubuntu-20.04)	35s
Build+test (clang, beta, ubuntu-20.04)	42s
Format	17s
ensure-header-updated	1m 3s
Build+test (clang, nightly, ubuntu-20.04)	50s
Check for documentation errors	17s
Build+test (clang, 1.61.0, ubuntu-20.04)	4m 38s
Build+test (gcc, stable, ubuntu-20.04)	45s
Check minimum versions	36s
Windows	1m 54s
Windows CMake, Debug configuration	1m 34s
Build+test (gcc, beta, ubuntu-20.04)	35s
Build+test (gcc, nightly, ubuntu-20.04)	36s
Windows CMake, Release configuration	1m 56s
Valgrind	1m 40s
Build+test (gcc, 1.61.0, ubuntu-20.04)	4m 47s
Build+test (macos-latest, clang, stable)	2m 10s
Clang Tidy	4s
Clippy	21s
Clippy nightly (optional)	18s
Miri	1m 1s
	26m 39s

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