Repro

{
  "rules": {
    "@typescript-eslint/prefer-function-type": "error"
  }
}

export {}
declare global {
    interface Function {
        (...args: any[]): any
    }
}

Expected Result

No errors because the type alias with a function type causes a syntax error (Duplicate identifier 'Function').

Actual Result

  5:9  error  Interface has only a call signature - use 'type Function = (...args: any[]) => any' instead  @typescript-eslint/prefer-function-type

Additional Info

Versions