Allow use of sparse registries #1447

Job	Run time
Cross-compile to aarch64	1m 42s
Build and test core crates (ubuntu-latest, 1.78)	1m 34s
Build and test core crates (ubuntu-latest, stable)	1m 40s
Build and test core crates (macos-14, 1.78)	1m 30s
Build and test core crates (macos-14, stable)	1m 19s
Build documentation (ubuntu-latest)	55s
Build and test (all features) (ubuntu-latest, 1.78)	2m 43s
Build and test core crates (windows-latest, 1.78)	4m 37s
Build and test (all features) (ubuntu-latest, stable)	2m 53s
Build and test core crates (windows-latest, stable)	4m 23s
Build and test (all features) (macos-14, 1.78)	2m 8s
Lint	1m 9s
Build and test (all features) (macos-14, stable)	2m 20s
cargo-compare extended tests (ubuntu-latest)	53s
Build and test (all features) (windows-latest, 1.78)	7m 8s
cargo-compare extended tests (macos-14)	1m 19s
Build and test (all features) (windows-latest, stable)	6m 49s
	45m 2s

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