Run CLI tests on all warehouses instead of just Postgres (#2094)

* Run CLI tests on all warehouses instead of just Postgres

- Add pull_request_target trigger to test-all-warehouses.yml
- Add workflow_call trigger for reusability
- Remove dbt 1.8.0 from matrix, run only on latest version
- Update elementary-ref to use PR head SHA for pull_request_target events
- Skip Slack notifications for PR failures to avoid spam
- Delete test-main-warehouse.yml (superseded by test-all-warehouses.yml)

Resolves ELE-5218

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

* Remove workflow_call trigger (not used by any other workflow)

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-all-warehouses.yml

@@ -1,5 +1,11 @@
 name: Test all warehouse platforms
 on:
+  pull_request_target:
+    branches: ["master"]
+    paths:
+      - elementary/**
+      - .github/**
+      - pyproject.toml
   workflow_dispatch:
     inputs:
       elementary-ref:
@@ -25,13 +31,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        dbt-version: ${{ inputs.dbt-version && fromJSON(format('["{0}"]', inputs.dbt-version)) || fromJSON('["1.8.0", null]') }}
+        dbt-version: ${{ inputs.dbt-version && fromJSON(format('["{0}"]', inputs.dbt-version)) || fromJSON('[null]') }}
         warehouse-type:
           [postgres, snowflake, bigquery, redshift, databricks_catalog, athena]
     uses: ./.github/workflows/test-warehouse.yml
     with:
       warehouse-type: ${{ matrix.warehouse-type }}
-      elementary-ref: ${{ inputs.elementary-ref }}
+      elementary-ref: ${{ inputs.elementary-ref || (github.event_name == 'pull_request_target' && github.event.pull_request.head.sha) || '' }}
       dbt-data-reliability-ref: ${{ inputs.dbt-data-reliability-ref }}
       dbt-version: ${{ matrix.dbt-version }}
       generate-data: ${{ inputs.generate-data || false }}
@@ -45,7 +51,8 @@ jobs:
       always() &&
       ! cancelled() &&
       ! contains(needs.test.result, 'success') &&
-      ! contains(needs.test.result, 'cancelled')
+      ! contains(needs.test.result, 'cancelled') &&
+      github.event_name != 'pull_request_target'
     uses: ./.github/workflows/notify_slack.yml
     with:
       result: "failure"