Tag to be used with the master branch of atlas/athena. Update(s) since 2.0.69: - Fixes in CheckerGccPlugins for thread safety checks in virtual calls, and inheritance checks for "Gaudi/..." headers; - Added an explicit check in AtlasCMake for a specific failure stemming from in-source builds; - Updated Acts to version v0.27.00; - Updated lwtnn to version 2.9; - Updated pyAMI to version 5.1.1; - Added a Findfmt.cmake module, and updated FindGaudi.cmake to use it;