fix: throw specific exception on empty list filters for time filters

[Maanik23]

Fixes #933

Summary

The _FilterByTime class (used by by_creation_time() and by_update_time()) was missing the empty list validation that other filter classes already have. Calling contains_any([]) or contains_none([]) on a time filter would silently produce a malformed filter instead of raising a clear error.

This brings _FilterByTime in line with _FilterByProperty and _FilterById, which already raise `WeaviateInvalidInputError` for empty input.

Changes

`weaviate/collections/classes/filters.py`

• Added `if len(dates) == 0` check to `_FilterByTime.contains_any()`
• Added `if len(dates) == 0` check to `_FilterByTime.contains_none()`
• Both raise `WeaviateInvalidInputError` with the same message format used elsewhere

`test/collection/test_filter.py`

• Extended `test_empty_input_contains_any` with cases for `by_creation_time()` and `by_update_time()`
• Added `test_empty_input_contains_none_time` covering `contains_none([])` on both time filter types

Why this matters

Without these checks, code like:

```python
collection.query.fetch_objects(
filters=Filter.by_creation_time().contains_any([])
)
```

would either crash with an opaque `IndexError` deep in the gRPC layer or send a malformed filter to the server. After this PR it raises a clear `WeaviateInvalidInputError` at construction time, matching the existing UX for property and ID filters.

Test plan

• Added unit tests for both `contains_any([])` and `contains_none([])` on `by_creation_time()` and `by_update_time()`
• Existing tests in `test_filter.py` continue to pass (no behavior change for non-empty inputs)
• Error message matches the existing format used in `_FilterByProperty` and `_FilterById`

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

[weaviate-git-bot]

To avoid any confusion in the future about your contribution to Weaviate, we work with a Contributor License Agreement. If you agree, you can simply add a comment to this PR that you agree with the CLA so that we can merge.

beep boop - the Weaviate bot 👋🤖

PS:
Are you already a member of the Weaviate Forum?

[Maanik23]

I have read and agree to the Weaviate Contributor License Agreement.