extends attribute should allow also arrays

[schamane]

Here example config for tsconfig.json:

{
  "$schema": "https://json.schemastore.org/tsconfig",
  "display": "Default",
  "extends": [
    "@tsconfig/recommended/tsconfig.json",
    "@tsconfig/node20/tsconfig.json",
    "@tsconfig/esm/tsconfig.json",
    "@tsconfig/strictest"
  ]
}

This will lead tsconfig-resolver to error:

The "path" argument must be of type string. Received an instance of Array

Array are allowed by Schema:

"extendsDefinition": {
      "properties": {
        "extends": {
          "description": "Path to base configuration file to inherit from (requires TypeScript version 2.1 or later), or array of base files, with the rightmost files having the greater priority (requires TypeScript version 5.0 or later).",
          "oneOf": [
            {
              "default": "",
              "type": "string"
            },
            {
              "default": [],
              "items": {
                "type": "string"
              },
              "type": "array"
            }
          ]
        }
      }
    }

[schamane]

Link for cross ref:
tsconfig/bases#167 (comment)