Also update MSRV in `flake.nix`
This got lost in an unfortunate merge.
Apparently I need to learn better how to use `jj` properly.
buildInputs = with pkgs; [
# Using the minimal profile with explicit "clippy" extension to avoid
# two versions of rustfmt
- (rust-bin.stable."1.60.0".minimal.override {
+ (rust-bin.stable."1.61.0".minimal.override {
extensions = [
"rust-src" # for rust-analyzer
"clippy"
