This reverts commit 09dde57e93.
Apparently, the rust-cbindgen bump wasn't the cause for the firefox
build error reported in https://github.com/NixOS/nixpkgs/pull/83247
(we could reproduce the build error even after
09dde57e93 applied).
For some reason it must have succeeded on hydra, as it's in the cache,
tricking us in believing 76458f89f4 broke
it initially.
So the build seems flaky of some sort - we haven't yet determined
whether it's luck, compiling with the right CPUs or something else. :-/
There's still some investigation to be done
(https://github.com/NixOS/nixpkgs/issues/84283), but no need to keep an
ineffective revert around.
Changes the default fetcher in the Rust Platform to be the newer
`fetchCargoTarball`, and changes every application using the current default to
instead opt out.
This commit does not change any hashes or cause any rebuilds. Once integrated,
we will start deleting the opt-outs and recomputing hashes.
See #79975 for details.
