fix: set explicit incremental_strategy='append' for test_result_rows.sql (#918)

* fix: remove incremental_strategy from test_result_rows.sql

The model no longer has a unique_key (removed in f5c062d), so using
merge incremental strategy causes Redshift to fail with:
'MERGE statement with a single WHEN clause is not enabled.'

Removing incremental_strategy lets dbt use the default append strategy
which is appropriate for this append-only table.

Fixes CORE-279

Co-Authored-By: Itamar Hartstein <haritamar@gmail.com>

* ci: update Python version to 3.10 for tests

The elementary-data package now requires Python >=3.10, so update
the test workflow to use Python 3.10 instead of 3.9.

Co-Authored-By: Itamar Hartstein <haritamar@gmail.com>

* fix: explicitly set incremental_strategy='append' for test_result_rows.sql

Co-Authored-By: Itamar Hartstein <haritamar@gmail.com>

* fix: add get_append_only_incremental_strategy macro for append-only tables

- Creates new macro that returns 'append' for Athena and None for other adapters
- Uses this macro in test_result_rows.sql instead of hardcoded 'append'
- Fixes Athena's default insert_overwrite strategy issue while allowing other
  adapters to use their defaults

Co-Authored-By: Itamar Hartstein <haritamar@gmail.com>

* fix: update get_append_only_incremental_strategy to return append for all except BigQuery

- Default now returns 'append' for all adapters
- BigQuery-specific override returns 'merge' (BigQuery doesn't support append)
- Removed Athena-specific override (now covered by default)

Co-Authored-By: Itamar Hartstein <haritamar@gmail.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Itamar Hartstein <haritamar@gmail.com>

Author: devin-ai-integration[bot]

.github/workflows/test-warehouse.yml

@@ -112,7 +112,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.9"
+          python-version: "3.10"
           cache: "pip"
 
       - name: Install Spark requirements

macros/utils/cross_db_utils/incremental_strategy.sql

@@ -17,3 +17,15 @@
 {% macro default__get_default_incremental_strategy() %}
   {% do return(none) %}
 {% endmacro %}
+
+{% macro get_append_only_incremental_strategy() %}
+  {% do return(adapter.dispatch("get_append_only_incremental_strategy", "elementary")()) %}
+{% endmacro %}
+
+{%- macro bigquery__get_append_only_incremental_strategy() %}
+  {% do return("merge") %}
+{% endmacro %}
+
+{% macro default__get_append_only_incremental_strategy() %}
+  {% do return("append") %}
+{% endmacro %}

models/edr/run_results/test_result_rows.sql

@@ -10,7 +10,7 @@
       "prev_timestamp_column": "detected_at",
       },
     table_type=elementary.get_default_table_type(),
-    incremental_strategy=elementary.get_default_incremental_strategy()
+    incremental_strategy=elementary.get_append_only_incremental_strategy()
   )
 }}