perf(metal): tune some kernel params for Kubernetes

The default values are too low, you may get an error in some cases
after a while (like viewing logs)

metal/cluster.yml

@@ -1,6 +1,7 @@
 - name: Create Kubernetes cluster
   hosts: metal
   roles:
+    - prerequisites
     - k3s
     - automatic_upgrade
 

metal/roles/prerequisites/tasks/main.yml

@@ -0,0 +1,8 @@
+- name: Adjust kernel parameters
+  ansible.posix.sysctl:
+    name: "{{ item.name }}"
+    value: "{{ item.value }}"
+  loop:
+    - {name: "fs.inotify.max_queued_events", value: 16384}
+    - {name: "fs.inotify.max_user_instances", value: 8192}
+    - {name: "fs.inotify.max_user_watches", value: 524288}