Fix 1 ClangInliner finding:

* The use of this symbol has been deprecated and marked for inlining. The function being deprecated is down_cast.

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#clrobot #base-casts.h

Tested:
    Local presubmit tests passed.
PiperOrigin-RevId: 862169325

Author: QUICHE team

quiche/quic/qbone/qbone_client.cc

@@ -50,7 +50,7 @@ QboneClient::QboneClient(QuicSocketAddress server_address,
 QboneClient::~QboneClient() { ResetSession(); }
 
 QboneClientSession* QboneClient::qbone_session() {
-  return static_cast<QboneClientSession*>(QuicClientBase::session());
+  return absl::static_cast<QboneClientSession*>(QuicClientBase::session());
 }
 
 void QboneClient::ProcessPacketFromNetwork(absl::string_view packet) {