Use arrays for kernel args and dns

nodes/_defaults.yaml

@@ -1,8 +1,21 @@
 schematicID: !schematic "_schematic.yaml"
 arch: amd64
 talosVersion: v1.11.3
-kernelArgs: talos.platform=metal console=tty0 init_on_alloc=1 slab_nomerge pti=on consoleblank=0 nvme_core.io_timeout=4294967295 printk.devkmsg=on selinux=1 lockdown=confidentiality
-dns0: 1.1.1.1
-dns1: 8.8.8.8
+kernelArgs:
+    - talos.platform=metal
+    - console=tty0
+    - init_on_alloc=1
+    - init_on_free=1
+    - slab_nomerge
+    - pti=on
+    - consoleblank=0
+    - nvme_core.io_timeout=4294967295
+    - printk.devkmsg=on
+    - selinux=1
+    - lockdown=confidentiality
+extraKernelArgs: []
+dns:
+    - 1.1.1.1
+    - 8.8.8.8
 ntp: nl.pool.ntp.org
 install: false