Rust 1.50.0 incorporated a Cargo change (rust-lang/cargo#8937) in
which cargo vendor erroneously changed permissions of vendored
crates. This was fixed in Rust
1.51.0 (rust-lang/cargo#9131). Unfortunately, this means that all
cargoSha256/cargoHashes produced during the Rust 1.50.0 cycle are
potentially broken.
This change updates cargoSha256/cargoHash tree-wide.
Fixes#121994.
API change:
`cargoParallelTestThreads` suggests that this attribute sets the
number of threads used during tests, while it is actually a boolean
option (use 1 thread or NIX_BUILD_CORES threads). In the hook, this
is replaced by a more canonical name `dontUseCargoParallelTests`.