Add the `CoreFoundation` framework #3163

Job	Run time
Check formatting	9s
Check MSRV	45s
Lint macOS x86_64	2m 30s
Lint iOS ARMv7s	2m 26s
Lint visionOS Aarch64 simulator	2m 27s
Lint GNUStep + exceptions	1m 50s
Lint header-translator	29s
Lint test-assembly	25s
Test macOS 15 Aarch64	1m 23s
Assembly tests	49s
Verify header translator output	1m 5s
Check framework features	0s
${{ ((matrix.test && 'Test') \|\| 'Build') }} ${{ matrix.name }}	0s
Test Compiler-RT	25s
Test GNUStep with libobjc2 v1.9	56s
Compiler UI	45s
Test on iOS simulator w. dinghy	0s
Test GNUStep with libobjc2 v2.0	1m 1s
Test GNUStep with libobjc2 v2.1 on nightly	1m 1s
Test GNUStep 32bit	1m 2s
	19m 28s

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