zonal.crop uses zones_ids; siblings stats/crosstab use zone_ids

[brendancol]

Summary

xrspatial.zonal.crop() accepts the parameter zones_ids (with the extra s),
while every other zonal function uses zone_ids for the same concept:

• zonal.stats(..., zone_ids=...)
• zonal.crosstab(..., zone_ids=...)
• zonal.crop(zones, values, zones_ids=...) <-- inconsistent

Users who learn the convention from stats/crosstab will get a
TypeError when calling crop, and vice versa.

API Consistency Sweep Context

Found by the api-consistency sweep against the zonal module
(2026-05-27). Severity: HIGH (Cat 1 — parameter naming drift, both names
exist concurrently in the public API).

Proposed Fix (Deprecation Shim)

Since this is a breaking rename, the fix should:

1. Accept both zone_ids (new, canonical) and zones_ids (legacy).
2. Emit a DeprecationWarning when zones_ids is used.
3. Raise if both are supplied.
4. Update the docstring and the in-tree examples/tests to use zone_ids.
5. Keep zones_ids working for at least one release cycle.

Test Plan

• Existing test_crop() keeps passing (uses zones_ids, will emit
  DeprecationWarning but still work).
• New test: calling crop(..., zone_ids=...) works identically.
• New test: passing both raises TypeError.
• New test: zones_ids triggers DeprecationWarning.