[v3-0-test] Fix AF3 TriggerDagRunLink to handle combinations of base_url (#54218) (#54760)

(cherry picked from commit 0204a89)

Co-authored-by: kandharvishnu <[email protected]>
Co-authored-by: Ash Berlin-Taylor <[email protected]>
Co-authored-by: Pierre Jeambrun <[email protected]>

Author: 4 people

airflow-core/src/airflow/utils/helpers.py

@@ -204,7 +204,7 @@ def build_airflow_dagrun_url(dag_id: str, run_id: str) -> str:
     http://localhost:8080/dags/hi/runs/manual__2025-02-23T18:27:39.051358+00:00_RZa1at4Q
     """
     baseurl = conf.get("api", "base_url", fallback="/")
-    return urljoin(baseurl, f"dags/{dag_id}/runs/{run_id}")
+    return urljoin(baseurl.rstrip("/") + "/", f"dags/{dag_id}/runs/{run_id}")
 
 
 # The 'template' argument is typed as Any because the jinja2.Template is too