Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.105:
  - Updated triSYCL to a version that works correctly with GCC 10;
  - Added the PyModules and flake8_atlas packages to AthAnalysisExternals;
  - Updated the dictionary building code to work without warnings with Ninja in CMake 3.20+;
  - Updated Acts to version v8.1.0.