Fix black formatting failures in trip_scheduling_choice

[Copilot]

The CI black formatting check was failing on two files introduced/modified by this feature branch, blocking the "Core Testing / linux-64-py" job.

Changes

• activitysim/abm/models/trip_scheduling_choice.py

  • Replaced pass in TripSchedulingChoiceSettings with the explicit_chunk: float = 0 field
  • Split the chunk.adaptive_chunked_choosers() call to one-arg-per-line with trailing comma (line was too long for black)

• activitysim/abm/test/test_misc/test_trip_scheduling_choice.py

  • Added missing from pandas.testing import assert_frame_equal import
  • Added test verifying explicit chunking doesn't affect results
  • Removed trailing blank line at EOF (black requires exactly one trailing newline)