docker: default to docker_29

According to https://github.com/moby/moby/blob/master/project/BRANCHES-AND-TAGS.md
docker 28.x is EOL.

pkgs/top-level/all-packages.nix

@@ -10670,7 +10670,7 @@ with pkgs;
     docker_29
     ;
 
-  docker = docker_28;
+  docker = docker_29;
   docker-client = docker.override { clientOnly = true; };
 
   docker-gc = callPackage ../applications/virtualization/docker/gc.nix { };