docs(user-guide): remove unsupported Between operator for Date filters (#22136)

## What

The Filters & Sorting user guide lists a **Between** operator for
**Date** fields, but this operator is not currently supported by the
product.

This removes it from the Date operators table.

| Field Type | Before | After |
|---|---|---|
| Date | Equals, Before, After, **Between**, Is empty | Equals, Before,
After, Is empty |

## Why

Avoids documenting a capability that does not currently exist.

The shared `ViewFilterOperand` enum does not define an `IS_BETWEEN`
operand, and the Date filter operands map does not include a Between
operator.

Related to #20932.

## Notes

- Documentation-only change.
- Only the canonical English source is edited.
- Localized copies under `packages/twenty-docs/l/*` are expected to be
regenerated by the existing docs translation workflow.

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packages/twenty-docs/user-guide/views-pipelines/capabilities/filters-and-sorting.mdx

@@ -21,7 +21,7 @@ Filters help you focus on specific records by showing only those that match your
 |------------|---------------------|
 | Text | Equals, Contains, Starts with, Ends with, Is empty |
 | Number | Equals, Greater than, Less than, Is empty |
-| Date | Equals, Before, After, Between, Is empty |
+| Date | Equals, Before, After, Is empty |
 | Select | Equals, Is any of, Is empty |
 | Checkbox | Is true, Is false |
 | Relation | Equals, Is empty |