Add missing space and remove duplicate operator values in WP_Date_Query PHPDoc.

[truptikanzariya]

In src/wp-includes/class-wp-date-query.php, the WP_Date_Query PHPDoc contains minor documentation issues:

A missing space after a period in the parameter description.
Current text:

@type string $month Optional when passing array.The month of the year.
@type string $day   Optional when passing array.The day of the month.

Duplicate mention of comparison operator values:
Current text:

Optional. The comparison operator. Accepts '=', '!=', '>', '>=',
'<', '<=', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN'. 'IN',
'NOT IN', 'BETWEEN', and 'NOT BETWEEN'. Comparisons support
arrays in some time-related parameters. Default '='.

Proposed fix:

• Ensure proper spacing after periods.
• Remove the duplicated operator list.

This improves documentation clarity and consistency.

[audrasjb]

In 61723:

Docs: Add missing space and remove duplicate operator values in WP_Date_Query docblocks.

Props truptikanzariya.
Fixes #64713.
See #64224.

[audrasjb]

In 61724:

Docs: Indentation fix after [61723].

See #64713, #64224.