message: test: remove unused function in lua_integration_test.cc
  Risk Level: low
  Testing: existing tests
  Docs Changes: N/A
  Release Notes: N/A
diff: @@ -445,7 +445,7 @@ config:
  request_handle:headers():add("signature_verification", "rejected")
  end
  - request_handle:releasePublicKey(pubkey)
  + request_handle:headers():add("verification", "done")
  end
  )EOF";
  @@ -473,6 +473,11 @@ config:
  ->value()
  .getStringView());
  + EXPECT_EQ("done", upstream_request_->headers()
  + .get(Http::LowerCaseString("verification"))
  + ->value()
  + .getStringView());
  +
  upstream_request_->encodeHeaders(default_response_headers_, true);
  response->waitForEndStream();
  