`@concurrent` main function runs on main actor

### Description

_No response_

### Reproduction

```swift
@main struct Foo {
  @concurrent static func main() async throws {
    print(Thread.isMainThread) // true
  }
}
```


### Expected behavior

Runs on the concurrent executor

### Environment

swift-driver version: 1.127.14.1 Apple Swift version 6.2 (swiftlang-6.2.0.19.8 clang-1700.3.19.1)

### Additional information

_No response_