Fix Apertus jinja template to accept both tool call format (chat/completion and responses)

Chat Completions API

{
  "type": "function",
  "function": {
    "name": "get_weather",
    "description": "Determine weather in my location",
    "strict": true,
    "parameters": {
      "type": "object",
      "properties": {
        "location": {
          "type": "string",
        },
      },
      "additionalProperties": false,
      "required": [
        "location",
        "unit"
      ]
    }
  }
}

Responses API

{
  "type": "function",
  "name": "get_weather",
  "description": "Determine weather in my location",
  "parameters": {
    "type": "object",
    "properties": {
      "location": {
        "type": "string",
      },
    },
    "additionalProperties": false,
    "required": [
      "location",
      "unit"
    ]
  }
}