ONNX Runtime CMake config file, put it to share/cmake/onnxruntime, see https://github.com/microsoft/onnxruntime/issues/3124#issuecomment-676239644

onnxruntimeConfig.cmake

# This will define the following variables:
#   onnxruntime_FOUND        -- True if the system has the onnxruntime library
#   onnxruntime_INCLUDE_DIRS -- The include directories for onnxruntime
#   onnxruntime_LIBRARIES    -- Libraries to link against
#   onnxruntime_CXX_FLAGS    -- Additional (required) compiler flags

include(FindPackageHandleStandardArgs)

# Assume we are in <install-prefix>/share/cmake/onnxruntime/onnxruntimeConfig.cmake
get_filename_component(CMAKE_CURRENT_LIST_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
get_filename_component(onnxruntime_INSTALL_PREFIX "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)

set(onnxruntime_INCLUDE_DIRS ${onnxruntime_INSTALL_PREFIX}/include)
set(onnxruntime_LIBRARIES onnxruntime)
set(onnxruntime_CXX_FLAGS "") # no flags needed


find_library(onnxruntime_LIBRARY onnxruntime
    PATHS "${onnxruntime_INSTALL_PREFIX}/lib"
)

add_library(onnxruntime SHARED IMPORTED)
set_property(TARGET onnxruntime PROPERTY IMPORTED_LOCATION "${onnxruntime_LIBRARY}")
set_property(TARGET onnxruntime PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${onnxruntime_INCLUDE_DIRS}")
set_property(TARGET onnxruntime PROPERTY INTERFACE_COMPILE_OPTIONS "${onnxruntime_CXX_FLAGS}")

find_package_handle_standard_args(onnxruntime DEFAULT_MSG onnxruntime_LIBRARY onnxruntime_INCLUDE_DIRS)