update atlas api import with new name

[alessandrofelder]

Description

What is this PR

• [x] Bug fix
• [ ] Addition of a new feature
• [ ] Other

Why is this PR needed? Workflows still had a remaining import for the atlas API using its old name.

What does this PR do? Updates the import call from bg_atlasapi to brainglobe_atlasapi

References

Closes #85

How has this PR been tested?

CI should pass, but didn't before in #85

Is this a breaking change?

No

Does this PR require an update to the documentation?

No

Checklist:

• [ ] The code has been tested locally - hoping to get away with just CI (here and on cellfinder) for this one-line change.
• [n/a] Tests have been added to cover all new functionality (unit & integration)
• [n/a] The documentation has been updated to reflect any changes
• [n/a] The code has been formatted with pre-commit

[alessandrofelder]

Probably worth re-running jobs on https://github.com/brainglobe/cellfinder/actions/runs/8423214341 before merging this, just to double-check.

[alessandrofelder]

(Just confirming brainmapper tests on cellfinder repo pass now this fix is in main ✅ )