flaky server test

[marten-seemann]

Server server accepting connections that completed the handshake handling packets creates a connection, if no token is required
/home/runner/work/quic-go/quic-go/server_test.go:457
  [FAILED] in [AfterEach] - /home/runner/work/quic-go/quic-go/quic_suite_test.go:48 @ 11/11/23 15:58:22.144
• [FAILED] [0.056 seconds]
TOP-LEVEL [AfterEach] Server server accepting connections that completed the handshake handling packets creates a connection, if no token is required
  [AfterEach] /home/runner/work/quic-go/quic-go/quic_suite_test.go:47
  [It] /home/runner/work/quic-go/quic-go/server_test.go:457

  [FAILED] missing call(s) to *quic.MockQUICConn.destroy(is anything) /home/runner/work/quic-go/quic-go/server_test.go:533
  In [AfterEach] at: /home/runner/work/quic-go/quic-go/quic_suite_test.go:48 @ 11/11/23 15:58:22.144

  Full Stack Trace
    github.com/quic-go/quic-go.glob..func24()
    	/home/runner/work/quic-go/quic-go/quic_suite_test.go:48 +0x27