Commit Message: when the AsyncTcpClient is being destroyed but it also has an active client connection, there's a crash since during the instance destruction, the ClientConnection object would also be destroyed, causing raiseEvent to be called back to AsyncTcpClient while it is being destroyed
Additional Description: Caught with the following stack trace:

Caught Segmentation fault, suspect faulting address 0x0
Backtrace (use tools/stack_decode.py to get line numbers):
Envoy version: ee8c765a07037033766ea556c032120b497152b3/1.27.0/Clean/RELEASE/BoringSSL
#0: __restore_rt [0x7d80ab903420]
#1: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLoggerImpl::onEvent() [0x58313528746b]
#2: Envoy::Tcp::AsyncTcpClientImpl::onEvent() [0x5831359da00a]
#3: Envoy::Network::ConnectionImplBase::raiseConnectionEvent() [0x583135f0521d]
#4: Envoy::Network::ConnectionImpl::raiseEvent() [0x583135e9fed9]
#5: Envoy::Network::ConnectionImpl::closeSocket() [0x583135e9f90c]
#6: Envoy::Network::ConnectionImpl::close() [0x583135e9e54c]
#7: Envoy::Network::ConnectionImpl::~ConnectionImpl() [0x583135e9de5c]
#8: Envoy::Network::ClientConnectionImpl::~ClientConnectionImpl() [0x5831355fd25e]
#9: Envoy::Tcp::AsyncTcpClientImpl::~AsyncTcpClientImpl() [0x5831359da247]
#10: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLoggerImpl::~FluentdAccessLoggerImpl() [0x583135289350]
#11: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLog::ThreadLocalLogger::~ThreadLocalLogger() [0x58313528adbf]
#12: Envoy::ThreadLocal::InstanceImpl::shutdownThread() [0x58313560373a]
#13: Envoy::Server::WorkerImpl::threadRoutine() [0x583135630c0a]
#14: Envoy::Thread::ThreadImplPosix::ThreadImplPosix()::{lambda()#1}::__invoke() [0x5831364e88d5]
#15: start_thread [0x7d80ab8f7609]

Risk Level: low
Testing: unit tests
Docs Changes: none
Release Notes: none
Platform Specific Features: none

Request variables

Key	Value
ref	ed09879
sha	26e2439
pr	35410
base-sha	b0cc284
actor	@ohadvano
message	async_tcp_client: remove callbacks if connection was not closed...
started	1722417628.832134
target-branch	main
trusted	false

Container image/s (as used in this CI run)

Envoy version (as used in this CI run)