Fix Forcings Engine test compile definition for test_all

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This PR fixes an issue where the test_all target is not compiled with -DNGEN_LUMPED_CONFIG_PATH.

This is because the definition is added with target_compile_definitions only to test_forcings_engine, but if that target exists, then test_all will include its objects. By replacing target_compile_definitions with add_compile_definitions , ensures test_all will have it defined.

Changes

• target_compile_definitions -> add_compile_definitions in tests/CMakeLists.txt

Checklist

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