Update flake.nix for v0.16.2 (#117)

Updates flake.nix version to 0.16.2 for the v0.16.2 release.

Author: wesm

flake.nix

@@ -15,7 +15,7 @@
         packages = {
           default = pkgs.buildGoModule {
             pname = "roborev";
-            version = "0.16.1";
+            version = "0.16.2";
 
             src = ./.;