fix: include key-only tag in merge fixture

Author: sd-db

CHANGELOG.md

@@ -7,6 +7,10 @@
 - Add support for Python UDFs ([#1336](https://github.com/databricks/dbt-databricks/pull/1336))
 - Add support for key-only `databricks_tags` for table and column tagging. This can now be configured by setting tag values to empty strings `""` or `None`. ([#1339](https://github.com/databricks/dbt-databricks/pull/1339))
 
+### Under the Hood
+
+- **BREAKING:** `databricks_tags` defined at different hierarchy levels (e.g. project-level and model-level) now merge additively instead of the child config completely replacing the parent.
+
 ## dbt-databricks 1.11.7 (Apr 17, 2026)
 
 ### Features
@@ -43,11 +47,6 @@
 - Fix catalog names with special characters (e.g., hyphens) not being quoted in `SHOW SCHEMAS` commands, causing `INVALID_IDENTIFIER` errors ([#1325](https://github.com/databricks/dbt-databricks/issues/1325))
 - Fix liquid clustering rendering on streaming table materialization [#1330](https://github.com/databricks/dbt-databricks/pull/1330)
 
-### Under the Hood
-
-- **BREAKING:** `databricks_tags` defined at different hierarchy levels (e.g. project-level and model-level) now merge additively instead of the child config completely replacing the parent.
-
-
 ## dbt-databricks 1.11.5 (Feb 19, 2026)
 
 ### Fixes

tests/functional/adapter/tags/fixtures.py

@@ -19,7 +19,7 @@
 tags_merged_sql = """
 {{ config(
     materialized = 'table',
-    databricks_tags = {'c': 'd'},
+    databricks_tags = {'c': 'd', 'k': ''},
 ) }}
 
 select cast(1 as bigint) as id, 'hello' as msg, 'blue' as color