Ensure fips mode is disabled by default for gitaly

What does this MR do?

Fixes the currently broken UBI pipelines (for example here: https://gitlab.com/gitlab-org/build/CNG/-/jobs/2619982757

This ensures that we aren't setting any value for FIPS_MODE by default in UBI unless we are in a FIPS pipeline. This is because gitaly is using ifdef in their makefile: https://gitlab.com/gitlab-org/gitaly/-/blob/master/Makefile#L81

Related issues

gitlab-org/gitaly#4296 (closed)

Fixes: gitlab-org/charts/gitlab#3362 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated