renaming env var IN_CIRCLECI to a broader name of IN_CI (#46567)
Summary:
The `IN_CIRCLECI` variable is a misnomer since the flag really indicates when we enable XML reporting because we want to run the test in CI. Since this doesn't necessarily mean CircleCI in particular, IN_CI is more accurate and general.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46567
Reviewed By: walterddr
Differential Revision: D24407642
Pulled By: janeyx99
fbshipit-source-id: 5e141a0571b914310a174a58ac0fde58e9521c6b
