fixed: do not enable tensorflow test without tensorflow on the system

tensorflow is too heavy to drag in as a dependency for everyone

pythonIntegrationTests.cmake

@@ -1,22 +1,29 @@
 file(MAKE_DIRECTORY ${PROJECT_BINARY_DIR}/tests/integration/HybridNewton)
-
-add_test(NAME
-          HybridNewton
-         COMMAND
-          ${Python3_EXECUTABLE}
-          -m unittest discover
-          ${PROJECT_SOURCE_DIR}/python/integration_tests/ml/hybrid_newton
-        WORKING_DIRECTORY
-          ${PROJECT_BINARY_DIR}/tests/integration/HybridNewton
-  )
-if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.22)
-  set(modifications
-      "PYTHONPATH=path_list_append:${opm-common_DIR}/python"
-      "PYTHONPATH=path_list_append:${CMAKE_CURRENT_BINARY_DIR}/python"
-      "FLOW_BINARY=set:$<TARGET_FILE:flow>"
-  )
-  set_tests_properties(HybridNewton PROPERTIES
-                       ENVIRONMENT_MODIFICATION
-                         "${modifications}"
-  )
+execute_process(
+  COMMAND "${Python3_EXECUTABLE}" -c "import tensorflow"
+  RESULT_VARIABLE PYTHON_HAS_TENSORFLOW
+  OUTPUT_QUIET
+  ERROR_QUIET
+)
+if(PYTHON_HAS_TENSORFLOW EQUAL 0)
+  add_test(NAME
+            HybridNewton
+           COMMAND
+            ${Python3_EXECUTABLE}
+            -m unittest discover
+            ${PROJECT_SOURCE_DIR}/python/integration_tests/ml/hybrid_newton
+          WORKING_DIRECTORY
+            ${PROJECT_BINARY_DIR}/tests/integration/HybridNewton
+    )
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.22)
+    set(modifications
+        "PYTHONPATH=path_list_append:${opm-common_DIR}/python"
+        "PYTHONPATH=path_list_append:${CMAKE_CURRENT_BINARY_DIR}/python"
+        "FLOW_BINARY=set:$<TARGET_FILE:flow>"
+    )
+    set_tests_properties(HybridNewton PROPERTIES
+                         ENVIRONMENT_MODIFICATION
+                           "${modifications}"
+    )
+  endif()
 endif()