rustfmt: update expected Rust edition
In this case it doesn't change anything, but we've been using 2021 for a
while now.
--- a/tests/test-check-rust-format.t Mon Jul 29 10:04:00 2024 +0200
+++ b/tests/test-check-rust-format.t Mon Jul 29 10:07:53 2024 +0200
@@ -7,5 +7,5 @@
Warning: Keep this in sync with hghave.py
$ RUSTFMT=$(rustup which --toolchain nightly-2024-07-16 rustfmt)
$ for f in `testrepohg files 'glob:**/*.rs'` ; do
- > $RUSTFMT --check --edition=2018 --unstable-features --color=never $f
+ > $RUSTFMT --check --edition=2021 --unstable-features --color=never $f
> done