ClickHouse: Add default deduplicate_merge_projection_mode

What does this merge request do and why?

This MR addresses a recent change in ClickHouse, where the default value of deduplicate_merge_projection_mode (throw) started causing an error:

This MR explicitly sets the value of the config property to drop, fixing the issue for users on a newer version of ClickHouse. I'm using 24.8.2.3.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Run gdk update.

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.