fix: skip tests on workflow dispatch (#70)

These are preview images, we don't deliver any guarantee.



<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Chores**
* Updated the Red Hat distro container workflow to conditionally skip
setup and test steps when manually triggered, reducing runtime and
resource usage for workflow_dispatch runs.
* Automated (non-manual) runs remain unchanged to preserve full test
coverage.
* Improves developer experience by enabling faster manual executions
without altering release behavior or user-facing functionality.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: leseb

.github/workflows/redhat-distro-container.yml

@@ -93,15 +93,18 @@ jobs:
           cache-to: type=gha,mode=max
 
       - name: Setup vllm for image test
+        if: github.event_name != 'workflow_dispatch'
         id: vllm
         uses: ./.github/actions/setup-vllm
 
       - name: Start and smoke test LLS distro image
+        if: github.event_name != 'workflow_dispatch'
         id: smoke-test
         shell: bash
         run: ./tests/smoke.sh
 
       - name: Integration tests
+        if: github.event_name != 'workflow_dispatch'
         id: integration-tests
         shell: bash
         run: ./tests/run_integration_tests.sh