Replace fetch with synchronize due to memory error (#5084)

Fix for Kubespray Issue #5059 (https://github.com/kubernetes-sigs/kubespray/issues/5059). There is a known issue with the 'fetch' module that will sometimes lead to it failing with a memory error. See ansible/ansible#11702 (https://github.com/ansible/ansible/issues/11702). I encountered this issue with the "Copy kubectl binary to ansible host" task in kubespray/roles/kubernetes/client/tasks/main.yml, and it caused my entire deployment to error out (see "Output of ansible run" above). Replacing 'fetch' with 'synchronize' fixes this issue.

roles/kubernetes/client/tasks/main.yml

@@ -90,11 +90,9 @@
   when: kubeconfig_localhost|default(false)
 
 - name: Copy kubectl binary to ansible host
-  fetch:
+  synchronize:
     src: "{{ bin_dir }}/kubectl"
     dest: "{{ artifacts_dir }}/kubectl"
-    flat: yes
-    validate_checksum: no
   become: no
   run_once: yes
   when: kubectl_localhost|default(false)