Drive-by improvements to convert_env_vars (#36062)

Author: uranusjr

airflow/providers/cncf/kubernetes/backcompat/backwards_compat_converters.py

@@ -71,19 +71,15 @@ def convert_port(port) -> k8s.V1ContainerPort:
 
 def convert_env_vars(env_vars: list[k8s.V1EnvVar] | dict[str, str]) -> list[k8s.V1EnvVar]:
     """
-    Convert a dictionary into a list of env_vars.
+    Coerce env var collection for kubernetes.
 
-    :param env_vars:
+    If the collection is a str-str dict, convert it into a list of ``V1EnvVar``s.
     """
-    if isinstance(env_vars, dict):
-        res = []
-        for k, v in env_vars.items():
-            res.append(k8s.V1EnvVar(name=k, value=v))
-        return res
-    elif isinstance(env_vars, list):
+    if isinstance(env_vars, list):
         return env_vars
-    else:
-        raise AirflowException(f"Expected dict or list, got {type(env_vars)}")
+    if isinstance(env_vars, dict):
+        return [k8s.V1EnvVar(name=k, value=v) for k, v in env_vars.items()]
+    raise AirflowException(f"Expected dict or list, got {type(env_vars)}")
 
 
 def convert_pod_runtime_info_env(pod_runtime_info_envs) -> k8s.V1EnvVar: