[Bug]: import - json in a string property is being interpreted as JSON

[baywet]

Describe the bug

#9228 introduced a regression.

The following description leads to this invalid TypeSpec definition after being imported.

@extension("x-oaiMeta", #{name: "Python Grader", group: "graders", example: """
{
  "type": "python",
  "name": "Example python grader",
  "image_tag": "2025-05-08",
  "source": """
def grade(sample: dict, item: dict) -> float:
    \"""
    Returns 1.0 if `output_text` equals `label`, otherwise 0.0.
    \"""
    output = sample.get("output_text")
    label = item.get("label")
    return 1.0 if output == label else 0.0
""",
}

When in fact it should result in the following.

@extension(
  "x-oaiMeta",
  #{
    name: "Python Grader",
    group: "graders",
    example: "{\n  \"type\": \"python\",\n  \"name\": \"Example python grader\",\n  \"image_tag\": \"2025-05-08\",\n  \"source\": \"\"\"\ndef grade(sample: dict, item: dict) -> float:\n    \\\"\"\"\n    Returns 1.0 if `output_text` equals `label`, otherwise 0.0.\n    \\\"\"\"\n    output = sample.get(\"output_text\")\n    label = item.get(\"label\")\n    return 1.0 if output == label else 0.0\n\"\"\",\n}\n",
  }
)

Reproduction

components:
  schemas:
    GraderPython:
      x-oaiMeta:
        name: Python Grader
        group: graders
        example: |
          {
            "type": "python",
            "name": "Example python grader",
            "image_tag": "2025-05-08",
            "source": """
          def grade(sample: dict, item: dict) -> float:
              \"""
              Returns 1.0 if `output_text` equals `label`, otherwise 0.0.
              \"""
              output = sample.get("output_text")
              label = item.get("label")
              return 1.0 if output == label else 0.0
          """,
          }

Here the example property in the extension should be considered a literal string, and not JSON that needs to be parsed.

Checklist

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• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.