client: lib_docker: shell: remove explicit workdir, use default

Defaults to the WORKDIR in the finalized Dockerfile produced by `build`.

client/src/docker/lib/internal/lib_docker.bash

@@ -511,7 +511,7 @@ function lib_docker::__shell()
   [ -z "$global_container" ] && lib_utils::die_fatal
   lib_utils::print_debug "Spawning shell in container '${global_container}'"
 
-  docker exec -it --user "$global_arg_user" --workdir / "$global_container" /bin/bash
+  docker exec -it --user "$global_arg_user" "$global_container" /bin/bash
 }
 
 function lib_docker::__exec()