gfe-relnote: (n/a) Deprecate --gfe2_reloadable_flag_quic_batch_writer_flush_after_mtu_probe.

PiperOrigin-RevId: 301254788
Change-Id: Ided83b7d8b093ae82dee9a41dac922d3856a86ef
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 007856b..cb2583e 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -5024,9 +5024,7 @@
   const uint32_t prior_flush_attempts = writer_->flush_attempts();
   connection_.SendMtuDiscoveryPacket(target_mtu);
   EXPECT_EQ(target_mtu, mtu_probe_size);
-  if (GetQuicReloadableFlag(quic_batch_writer_flush_after_mtu_probe)) {
-    EXPECT_EQ(writer_->flush_attempts(), prior_flush_attempts + 1);
-  }
+  EXPECT_EQ(writer_->flush_attempts(), prior_flush_attempts + 1);
 }
 
 // Tests whether MTU discovery does not happen when it is not explicitly enabled