Fix self-referencing spawn alias in runner

crdt-demo/runner.zig

@@ -2,7 +2,7 @@
 //! CRDT server binary, then waits for the server to exit.
 
 const std = @import("std");
-const spawn = spawn;
+const spawn = std.process.spawn;
 
 pub fn main(init: std.process.Init) !void {
     const io = init.io;