Fix lint drift introduced by merging v0.8.0 into lint-pass

- add_stationing_referent.py: black reformat (new drift from v0.8.0).
- update_fallback_position.py: v0.8.0's changes to this file made the
  ifcopenshell.util.unit import (added in an earlier commit here) unused;
  removed per ruff.

src/ifcopenshell-python/ifcopenshell/api/alignment/add_stationing_referent.py

@@ -58,7 +58,11 @@ def add_stationing_referent(
     if on_basis_curve is None:
         on_basis_curve = True
 
-    curve = ifcopenshell.api.alignment.get_basis_curve(alignment) if on_basis_curve else ifcopenshell.api.alignment.get_curve(alignment)
+    curve = (
+        ifcopenshell.api.alignment.get_basis_curve(alignment)
+        if on_basis_curve
+        else ifcopenshell.api.alignment.get_curve(alignment)
+    )
 
     object_placement = None
     representation = None

src/ifcopenshell-python/ifcopenshell/api/alignment/update_fallback_position.py

@@ -18,7 +18,6 @@
 
 import ifcopenshell
 import ifcopenshell.util.placement
-import ifcopenshell.util.unit
 from ifcopenshell import entity_instance