Update Rust crate proptest to 1.4.0 #466

Job	Run time
Build and test core crates (ubuntu-latest, 1.70)	4m 11s
Build and test (all features) (ubuntu-latest, 1.70)	5m 18s
Build and test core crates (ubuntu-latest, stable)	3m 5s
Build and test core crates (macos-latest, 1.70)	5m 19s
Build and test (all features) (ubuntu-latest, stable)	4m 44s
Cross-compile to aarch64	3m 23s
Build and test core crates (macos-latest, stable)	3m 13s
Build and test (all features) (macos-latest, 1.70)	5m 43s
Build and test (all features) (macos-latest, stable)	5m 55s
Build and test core crates (windows-latest, 1.70)	6m 43s
Build and test core crates (windows-latest, stable)	8m 28s
Build and test (all features) (windows-latest, 1.70)	9m 51s
Build documentation (ubuntu-latest)	1m 19s
Build and test (all features) (windows-latest, stable)	8m 28s
Lint	51s
cargo-compare extended tests (ubuntu-latest)	2m 1s
cargo-compare extended tests (macos-latest)	4m 55s
	1h 23m 27s

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