fix: ensure final week renders when endMonth clips the calendar

[gpbl]

This PR addresses the issue reported by @Toni997 where, when endMonth is set, the final month’s last week is truncated and missing the remaining table cells. The fix ensures the grid still renders through the end of that week while respecting the endMonth constraint.

Changes

• Adjust grid date generation to stop at the earlier of the display months’ end week, so the last row is fully rendered instead of truncating.
• Update max-date tests to expect the final week boundary.

Breaking change note

No public API changed, so semver-wise it’s a bugfix (patch) rather than a breaking/major change. We should however note in the changelog that the last month with endMonth now renders a full final week row; consumers with brittle DOM/snapshot/visual tests or custom CSS might see diffs and need to update snapshots/styles.

Result

Empty table cells are rendered in the last week: