Get rid of code for OpenSSL that has old QUIC API

configure.ac

@@ -1272,20 +1272,11 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <openssl/ssl.h>]],
                     AC_CHECK_FUNCS(SSL_set_quic_early_data_enabled)
                     LIBS=$_quic_saved_LIBS
                   ],
-                  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <openssl/ssl.h>]],
-                                   [[
-                                     #ifdef SSL_MODE_QUIC_HACK
-                                     #else
-                                     # error no hack for quic
-                                     #endif
-                                   ]])
-                  ],
-                  [AC_MSG_RESULT([yes]); enable_quic=yes; enable_quic_old_api=yes],
-                  [AC_MSG_RESULT([no])])
+                  [
+                    AC_MSG_RESULT([no])
                   ])
 
 AM_CONDITIONAL([ENABLE_QUIC], [test "x$enable_quic" = "xyes"])
-AM_CONDITIONAL([ENABLE_QUIC_OLD_API], [test "x$enable_quic_old_api" = "xyes"])
 TS_ARG_ENABLE_VAR([use], [quic])
 AC_SUBST(use_quic)
 

iocore/net/quic/Makefile.am

@@ -40,18 +40,11 @@ QUICPPProtector_impl = QUICPacketPayloadProtector_boringssl.cc
 QUICTLS_impl = QUICTLS_boringssl.cc
 QUICKeyGenerator_impl = QUICKeyGenerator_boringssl.cc
 else
-if ENABLE_QUIC_OLD_API
-QUICPHProtector_impl = QUICPacketHeaderProtector_legacy.cc
-QUICPPProtector_impl = QUICPacketPayloadProtector_legacy.cc
-QUICTLS_impl = QUICTLS_legacy.cc
-QUICKeyGenerator_impl = QUICKeyGenerator_legacy.cc
-else
 QUICPHProtector_impl = QUICPacketHeaderProtector_openssl.cc
 QUICPPProtector_impl = QUICPacketPayloadProtector_openssl.cc
 QUICTLS_impl = QUICTLS_openssl.cc
 QUICKeyGenerator_impl = QUICKeyGenerator_openssl.cc
 endif
-endif
 
 QLog_impl = qlog/QLogEvent.cc qlog/QLogFrame.cc qlog/QLog.cc