Rename `loki.build`

[reuterbal]

What maintenance does this project need?

Pytest skips subdirectories called build when collecting tests, which means the tests defined in loki/build/tests are never run. See the following links for more details:
pytest-dev/pytest#12621 (reply in thread)
pytest-dev/pytest#12625

We should rename loki.build to something else to enable testing this component.

Organisation

No response