Remove synthetic flat-format regression test

Drop the JSON post-processing helper and its test. Coverage will instead
come from a follow-up CI bump to a Keras version that natively emits the
flat input_layers/output_layers form, at which point the existing
readme_example_main test exercises this code path against real Keras
output.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Dobiasd

test/CMakeLists.txt

@@ -58,11 +58,6 @@ add_custom_command ( OUTPUT readme_example_model.json
                      COMMAND bash -c "${Python3_EXECUTABLE} ${FDEEP_TOP_DIR}/keras_export/convert_model.py readme_example_model.keras readme_example_model.json"
                      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/)
 
-add_custom_command ( OUTPUT readme_example_flat_format_model.json
-                     DEPENDS readme_example_model.json
-                     COMMAND bash -c "${Python3_EXECUTABLE} ${FDEEP_TOP_DIR}/test/readme_example_flat_format_generate.py readme_example_model.json readme_example_flat_format_model.json"
-                     WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/)
-
 hunter_add_package(doctest)
 find_package(doctest CONFIG REQUIRED)
 
@@ -80,7 +75,6 @@ _add_test(test_model_variable_test test_model_variable.json)
 _add_test(test_model_autoencoder_test test_model_autoencoder.json)
 _add_test(test_model_sequential_test test_model_sequential.json)
 _add_test(readme_example_main readme_example_model.json)
-_add_test(readme_example_flat_format_test readme_example_flat_format_model.json)
 
 add_custom_target(unittest
   COMMAND test_model_exhaustive_test
@@ -89,7 +83,6 @@ add_custom_target(unittest
   COMMAND test_model_autoencoder_test
   COMMAND test_model_sequential_test
   COMMAND readme_example_main
-  COMMAND readme_example_flat_format_test
 
   COMMENT "Running unittests\n\n"
   VERBATIM