CircleCI docker is missing the diff command affecting PRs

Created by: williamfgc

Describe the bug Current CircleCI docker images are missing the diff command, thus preventing new PR to be merged.

To Reproduce Check current PRs failing when configuring with CMake Exmaple: https://circleci.com/gh/ornladios/ADIOS2/32181?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-checks-link

CMake Error at CMakeLists.txt:227 (message):
  diff command is required for testing