OMPT Target Offload Support (#17)

- Porting from https://github.com/ROCm/omnitrace/pull/411
- Improve OMPT support
- Add OpenMP target example to testing
- Update Timemory submodule to use ROCm/Timemory rather than NERSC/Timemory
- Update `actions/upload-artifacts` to v4
- Standardize the `cmake_minimum_required` to 3.18.4 across workflows, project, and examples
- Updated Ubuntu 20.04 workflows

scripts/test-find-package.sh

@@ -112,7 +112,7 @@ verbose-run cp -v -r ${EXAMPLE_DIR}/${EXAMPLE_NAME}/* ${SOURCE_DIR}/
 verbose-run pushd ${SOURCE_DIR}
 
 cat << EOF > CMakeLists.txt
-cmake_minimum_required(VERSION 3.16.0 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.18.4.0 FATAL_ERROR)
 
 project(test LANGUAGES C CXX)