ya-provider: update presets.json.j2

[etam]

Current example:

{
  "ver": "V1",
  "active": [
    "wasmtime",
    "vm"
  ],
  "presets": [
    {
      "name": "wasmtime",
      "exeunit-name": "wasmtime",
      "pricing-model": "linear",
      "initial-price": 0.0,
      "usage-coeffs": {
        "golem.usage.duration_sec": 0.00005,
        "golem.usage.cpu_sec": 0.0001
      }
    },
    {
      "name": "vm",
      "exeunit-name": "vm",
      "pricing-model": "linear",
      "initial-price": 0.0,
      "usage-coeffs": {
        "golem.usage.duration_sec": 0.00005,
        "golem.usage.cpu_sec": 0.0001
      }
    }
  ]
}

also try to generate a pretty-printed json, so that ya-provider doesn't change formatting, causing false "changed" in ansible.

[etam]

followup issue: golemfactory/yagna#2423