[rejected AI] do not append fill_with in slice when slice count evenly divides iterable

[pylrn]

Fixes #2118

Problem

When slices evenly divides len(seq) (e.g. [1, 2, 3, 4]|slice(4, 'foo')), slices_with_extra = length % slices is 0.
Because the check was slice_number >= slices_with_extra, every slice satisfied slice_number >= 0 and had fill_with appended, adding an extra unnecessary element to every sub-list even though all slices were already full and of equal length.

Fix

• Updated the fill_with check in sync_do_slice in src/jinja2/filters.py to require slices_with_extra > 0 in addition to slice_number >= slices_with_extra.
• Added test assertions to tests/test_filters.py and tests/test_async_filters.py.

[davidism]

https://palletsprojects.com/contributing/llm-ai