Trying to connecting to non-existing database using `PostgresClient`, queries hang indefinitely with no error thrown

[ahoppen]

When using PostgresClient and trying to connect to a database that doesn’t exist, no error is thrown. Instead, any attempt to run a query just hangs, no error is thrown. When connecting using PostgresConnection, an error is thrown at connection time.

To reproduce, add the following test to IntegrationTests/PostgresNIOTests.swift and run it. Notice how it just hangs, I would have expected an error to be thrown from query.

func testConnectToNonexistingDatabase() async throws {
    let config = PostgresClient.Configuration(
        host: env("POSTGRES_HOSTNAME") ?? "localhost",
        port: env("POSTGRES_PORT").flatMap(Int.init(_:)) ?? 5432,
        username: env("POSTGRES_USER") ?? "test_username",
        password: env("POSTGRES_PASSWORD") ?? "test_password",
        database: "does_not_exist",
        tls: .disable
    )
    let client = PostgresClient(configuration: config)
    try await withThrowingTaskGroup { taskGroup in
        taskGroup.addTask {
            await client.run()
        }
        try await client.query("SELECT 1")
    }
}