BeanOutputConverter getFormat() and convert() format mismatch for List types

Please do a quick search on GitHub issues first, there might be already a duplicate issue for the one you are about to create.
If the bug is trivial, just go ahead and create the issue. Otherwise, please take a few moments and fill in the following sections:

Bug description

• prompt
• Your response should be in JSON format.
  Do not include any explanations, only provide a RFC8259 compliant JSON response following this format without deviation.
  Do not include markdown code blocks in your response.
  Remove the ```json markdown from the output.
  Here is the JSON Schema instance your output must adhere to:

  "$schema" : "https://json-schema.org/draft/2020-12/schema",
  "type" : "array",
  "items" : {
    "type" : "object",
    "properties" : {
      "sql" : {
        "type" : "string",
        "description" : "SQL语句"
      },
      "stepName" : {
        "type" : "string",
        "description" : "步骤名称"
      }
    },
    "required" : [ "sql", "stepName" ],
    "additionalProperties" : false
  }
}```
- getFormat() generates: {"type":"array","items":[...]}
- convert() expects: [{...},{...}]

**Environment**
spring ai 1.1.3

When LLM follows the format from getFormat(), convert() fails with:
MismatchedInputException: Cannot deserialize value of type ArrayList from Object value

Start by tracing BeanOutputConverter.getFormat() and convert() for List types, using the reported schema and Spring AI 1.1.3 behavior to reproduce the mismatch. Confirm that the format emitted for a list matches the structure convert() deserializes, and verify the bug is covered by a passing regression test.