feat(xtask): update nix

crates/xtask/src/bump.rs

@@ -166,6 +166,7 @@ pub fn run(args: BumpVersion) -> Result<()> {
     update_crates(&current_version, &next_version)?;
     update_makefile(&next_version)?;
     update_cmake(&next_version)?;
+    update_nix(&next_version)?;
     update_npm(&next_version)?;
     update_zig(&next_version)?;
     tag_next_version(&next_version)?;
@@ -181,6 +182,7 @@ fn tag_next_version(next_version: &Version) -> Result<()> {
             "Cargo.toml",
             "Makefile",
             "build.zig.zon",
+            "flake.nix",
             "crates/cli/Cargo.toml",
             "crates/cli/npm/package.json",
             "crates/cli/npm/package-lock.json",
@@ -264,6 +266,26 @@ fn update_cmake(next_version: &Version) -> Result<()> {
     Ok(())
 }
 
+fn update_nix(next_version: &Version) -> Result<()> {
+    let nix = std::fs::read_to_string("flake.nix")?;
+    let nix = nix
+        .lines()
+        .map(|line| {
+            if line.trim_start().starts_with("version =") {
+                format!("          version = \"{next_version}\";")
+            } else {
+                line.to_string()
+            }
+        })
+        .collect::<Vec<_>>()
+        .join("\n")
+        + "\n";
+
+    std::fs::write("flake.nix", nix)?;
+
+    Ok(())
+}
+
 fn update_crates(current_version: &Version, next_version: &Version) -> Result<()> {
     let mut cmd = std::process::Command::new("cargo");
     cmd.arg("workspaces").arg("version");