[server_call_test] fix compilation (#36856)

Closes #36856

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/36856 from ctiller:ct b62ab66318
PiperOrigin-RevId: 641447391

test/core/call/server_call_test.cc

@@ -38,7 +38,9 @@ class ServerCallTest : public YodelTest {
  protected:
   using YodelTest::YodelTest;
 
-  ~ServerCallTest() { grpc_metadata_array_destroy(&publish_initial_metadata_); }
+  ~ServerCallTest() override {
+    grpc_metadata_array_destroy(&publish_initial_metadata_);
+  }
 
   grpc_call* InitCall(ClientMetadataHandle client_initial_metadata) {
     CHECK_EQ(call_, nullptr);