Nested immutable array schemas generate syntactically-invalid readonly readonly type

[duncanbeevers]

Description

Nested immutable array schemas generate syntactically-invalid readonly readonly type.

const result = transformSchemaObject({
  type: "object",
  properties: {
    values: {
      type: "array",
      items: {
        type: "array",
        items: {
          type: "string",
        },
      },
    },
  },
})

expect(result).toBe(`{
  readonly values?: readonly (readonly string[])[];
}`, { ctx: { immutableTypes: true } })

/*
- Expected
+ Received

  {
-   readonly values?: readonly (readonly string[])[];
+   readonly values?: readonly readonly string[][];
  }
*/

Name	Version
openapi-typescript	6.4.5
Node.js	18.16.1
OS + version	macOS 13.5

Checklist

• My OpenAPI schema passes the Redocly validator (npx @redocly/cli@latest lint)
• I’m willing to open a PR (see CONTRIBUTING.md)