chore: update rust nightly in nix

whilst fmt is using nightly it doesnt appear that clippy is

previous attempts to update the rustfmt nightly version have resulted
in a large number of errors which needed resolving. the change was
backed out because of other priorities.

It appears  now that clippy is not using the nightly version
and there are no regressions

1 files changed, 1 insertions, 1 deletions

diff --git a/flake.nix b/flake.nix
index 26fda20..dfd6325 100644
--- a/flake.nix
+++ b/flake.nix
@@ -22,7 +22,7 @@
             # ideally this wouldn't be pinned to a specific nightly version but
             # selectLatestNightlyWith isn't support with mixed toolchains
             # https://github.com/oxalica/rust-overlay/issues/136
-            (lib.hiPrio rust-bin.nightly."2023-12-01".rustfmt)
+            (lib.hiPrio rust-bin.nightly."2024-04-05".rustfmt)
             # (rust-bin.stable.latest.override { extensions = [ "rust-analyzer" ]; })
             rust-bin.stable.latest.default
           ];