Add schematic `extraKernelArgs` into `machine.install.extraKernelArgs` automatically

[budimanjojo]

Right now, the extraKernelArgs added into schematic is not being respected if you apply the configuration to your existing cluster. See siderolabs/talos#8008 for more information.

I think it makes sense for talhelper to add schematic.customization.extraKernelArgs to machine.install.extraKernelArgs automatically so the kernel arguments are being applied to the machine because you should always expect them to be there if you define them in your talconfig.yaml.
But there's a small problem because you might already have a patch like this in your talconfig.yaml:

nodes:
  - hostname: host1
    ipAddress: 1.2.3.4
    patches:
      - op: add
        path: /machine/install/extraKernelArgs
        value:
          - talos.logging.kernel=udp://1.2.3.4:1234

And this will make the list become overwritten.
This makes this not consistent but it's what it's I think.