Update dependencies, Xcode version and minimum deployment target #2330

Job	Run time
Check MSRV	1m 25s
Lint macOS 64bit	2m 18s
Check formatting	7s
Lint iOS 32bit	56s
Lint GNUStep + exceptions	1m 23s
Lint header-translator	30s
Lint test-assembly	21s
Test macOS 12	2m 5s
Check icrate features	1s
Verify header translator output	1s
${{ matrix.name }}	1s
Assembly tests	1s
${{ matrix.name }}	1s
Test on iOS simulator w. dinghy	1s
Test Compiler-RT	1s
Compiler UI	1s
	9m 13s

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