`//test/integration:tcp_tunneling_integration_test` is extremely flakey

This has been flakey a long time - but it appears it just got a **lot** worse

afaict its failing across the board on tests - but it seems particularly bad for san tests

Its not hard to trigger locally and seems related to https://github.com/envoyproxy/envoy/commit/dbd0cad19aac2b43ea0e8c47b7c3889252603b2f

```console
[ RUN ] HttpAndIpVersions/ConnectTerminationIntegrationTest.UpstreamClose/IPv4_Http3Downstream_HttpUpstreamHttpParserNghttp2Legacy
test/integration/tcp_tunneling_integration_test.cc:325: Failure
Value of: response_->waitForReset()
Actual: false (Stream finished while waiting for reset
IntegrationStreamDecoder state:
saw_end_stream_=1
saw_reset_=0
headers_=':status', '200'
'date', 'Thu, 12 Jun 2025 08:25:06 GMT'
'server', 'envoy'

continue_headers_=null
body_=there!
trailers_=null)
Expected: true
Stack trace:
0x56173b604cb1: Envoy::(anonymous namespace)::ConnectTerminationIntegrationTest_UpstreamClose_Test::TestBody()
0x5617436a0d6d: testing::internal::HandleSehExceptionsInMethodIfSupported<>()
0x56174366972b: testing::internal::HandleExceptionsInMethodIfSupported<>()
0x561743644b19: testing::Test::Run()
0x56174364594d: testing::TestInfo::Run()
... Google Test internal frames ...

test/integration/http_integration.cc:385: Failure
Expected equality of these values:
codec_client_->numActiveRequests()
Which is: 1
0
test requires explicit cleanupUpstreamAndDownstream
Stack trace:
0x56173b85cf00: Envoy::HttpIntegrationTest::~HttpIntegrationTest()
0x56173b6dbf6e: Envoy::HttpProtocolIntegrationTest::~HttpProtocolIntegrationTest()
0x56173b5f5b1a: Envoy::(anonymous namespace)::ConnectTerminationIntegrationTest::~ConnectTerminationIntegrationTest()
0x56173b604776: Envoy::(anonymous namespace)::ConnectTerminationIntegrationTest_UpstreamClose_Test::~ConnectTerminationIntegrationTest_UpstreamClose_Test()
0x56173b6047ba: Envoy::(anonymous namespace)::ConnectTerminationIntegrationTest_UpstreamClose_Test::~ConnectTerminationIntegrationTest_UpstreamClose_Test()
0x56174366a212: testing::Test::DeleteSelf_()

```